Shulchan Arukh, Orach Chayim 103:2-104:1

Hoo boy, buckle up, fellow data-miners of the Daf! We're about to dive into a sugya that's as intricate as a doubly-linked list and as critical as error handling in production code. Today's mission: Shulchan Arukh, Orach Chayim 103:2-104:1. We'll be dissecting the "bug reports" of biological interrupts during prayer and how to gracefully handle them with the power of systems thinking. Think of it as debugging your spiritual operating system!

Problem Statement – The "Bug Report" in the Sugya

Our central "bug report" revolves around unexpected biological events that occur during the Amidah prayer. These aren't just minor glitches; they can potentially derail the entire prayer session, introducing "exceptions" that require specific handling protocols. The core issue is how to maintain the integrity and flow of the Amidah, a high-stakes, real-time application, when faced with involuntary system interruptions.

The problem can be broken down into several key components:

• Event Types: What kind of biological interrupts are we dealing with? The text explicitly mentions passing gas ("gas went out from below") and sneezing ("one who 'sneezes'"). These are distinct events with potentially different severities and required responses.
• Contextual Dependencies: The appropriate response is heavily dependent on the prayer environment. Is the user praying alone at home (a local, private instance) or with a congregation (a shared, public instance)? The presence of others introduces social constraints and potential embarrassment, which are critical variables in the decision-making process.
• Severity Assessment: Not all "bugs" are equal. The text differentiates between the severity of passing gas and a sneeze. A sneeze is even further categorized by its origin ("from below" vs. "from above"). This suggests a multi-factor risk assessment is in play.
• Interruption vs. Disruption: The sugya grapples with the concept of "interruption." Is a necessary action to address a biological issue an interruption that invalidates the prayer, or a disruption that can be managed with a specific recovery procedure? The system aims to minimize actual interruptions that require restarting the entire process.
• Recovery Procedures: When an interrupt does occur, what are the prescribed "recovery scripts"? These range from waiting for a smell to dissipate, to physically moving, to reciting specific "error messages" (like the "Master of the world..." prayer), to even restarting the entire prayer from the beginning.
• Performance Impact: The speed of prayer is a parameter. If an interruption causes a delay exceeding the time it takes to complete the entire Amidah, the system dictates a full reset. This highlights the importance of efficient processing and minimizing downtime.
• Social Protocol: The presence of a congregation introduces a significant "social overhead." The need to avoid embarrassment ("great embarrassment for oneself") modifies the standard operating procedure, prioritizing discretion over strict adherence to certain recovery steps.

Essentially, we have a system (the Amidah prayer) that is designed for continuous, focused execution. When unexpected "input streams" (biological events) arrive, the system needs to have robust error handling and recovery mechanisms to ensure that the prayer is not corrupted and can be completed successfully. The challenge lies in defining these mechanisms precisely, considering various environmental factors and event severities, and ensuring the user understands the correct "exception handling" flow.

Text Snapshot

Let's zero in on the key lines that define our operating parameters:

Shulchan Arukh, Orach Chayim 103:2:

If one was standing in prayer and gas went out from below, one waits until the smell dissipates and then go back and pray.

Shulchan Arukh, Orach Chayim 103:3:

If one had an urge to pass gas from below and is in a lot of discomfort and can't contain oneself, one walks 4 cubits back and passes the gas, waits until the smell dissipates from one, and then says "Master of the world, You created us with many holes and cavities; It is revealed and known before You our disgrace and shame, disgrace and shame in our life, worm and maggot in our death.", and then goes back to one's place and goes back to the place one left off.

Shulchan Arukh, Orach Chayim 103:3, Gloss (Terumat Hadeshen Siman 16):

And see above in Siman 85. There are those who say that all this is [referring to] when one is praying in one's home, but when praying with the congregation, where there would be a great embarrassment for oneself [if one were to do as described above], one does not need to distance oneself at all backwards, and one also shouldn't say the "Master [of the worlds]..." [prayer that was mentioned above], rather one should just wait until the smell dissipates from one. And such is how we practice.

Shulchan Arukh, Orach Chayim 103:4:

One who "sneezes" during [the middle of] one's prayer [i.e. Amidah]: [if it's] from below (i.e. one passes gas), it's a bad sign; [if it's] from above (i.e. a sneeze from one nose), it's a good sign.

Shulchan Arukh, Orach Chayim 104:1:

One may not interrupt during one's prayer [i.e. Amidah]. And even if a Jewish king is inquiring about one's well-being, one may not respond to him. But [regarding responding to] a king of the nations of the world, if one is able to shorten [one's prayer], meaning that one would say the beginning of the blessing and its end before the [king] reaches one, one should shorten it. Or if [one's on the road and] one is able to veer off the road, [then] one should veer off, but one may not interrupt by talking. And if it's impossible for one [to do so], one may interrupt.

Shulchan Arukh, Orach Chayim 104:1:

In any circumstance where one interrupted, if one delayed long enough to finish all of it [i.e. the Amidah prayer], one must return to the beginning; and if not, then one returns to the beginning of the blessing that one interrupted. And if one interrupted in one of the first three [blessings], one returns to the beginning; and if it was in one of the latter ones [i.e. three blessings], one returns to [the blessing of] "R'tzei".

Shulchan Arukh, Orach Chayim 104:1:

This [thing] that we said: "that if one delayed long enough to finish all of it [i.e. the Amidah prayer]", we calculate [that time] based on the speed of] the one reading (i.e. praying). If one conversed during the [Amidah] prayer, the law regarding the matter of returning [to an earlier part of the prayer] is like the law regarding interruptions mentioned in this siman.

Shulchan Arukh, Orach Chayim 104:1:

One may not interrupt [the Amidah], not for [the responses in the] Kaddish and not for Kedusha. Rather, one should be silent and focus on what the prayer leader is saying and it will be [considered] like one is answering.

Shulchan Arukh, Orach Chayim 104:1:

After one finished the eighteen blessings [of the Amidah], [but] before [one said] "Elokai, netzor", one may answer Kedusha, Kaddish, and Barchu.

Flow Model – Decision Tree for Biological Interrupts

Let's visualize the decision-making process for handling biological interrupts during Amidah as a branching logic tree. This is like tracing the execution path of our prayer application.

• Start: Amidah Prayer in Progress

  • Event Detected: Biological Interrupt?
    • YES:
      • Event Type Identified:
        • Type A: Passing Gas (from below)
          • Context: Praying at Home (Private Instance)?
            • YES:
              • Severity: Urge Uncontainable & High Discomfort?
                • YES:
                  • Action: Walk 4 cubits back.
                  • Action: Pass gas.
                  • Action: Wait for smell to dissipate from self.
                  • Action: Recite "Master of the world..." prayer (internalized for processing).
                  • Action: Return to original prayer location.
                  • Action: Resume prayer at point of interruption.
                • NO (Gas released without uncontainable urge/discomfort):
                  • Action: Wait for smell to dissipate from oneself.
                  • Action: Resume prayer at point of interruption.
            • NO (Praying with Congregation - Public Instance):
              • Severity: High Embarrassment Concern?
                • YES:
                  • Action: Wait for smell to dissipate from oneself (minimal physical movement).
                  • Action: Do NOT recite "Master of the world..." prayer.
                  • Action: Resume prayer at point of interruption.
                • NO (Embarrassment is minimal/manageable):
                  • (This scenario is less explicitly defined but implies a stricter adherence to private protocols if possible).
                  • Action: Wait for smell to dissipate from oneself.
                  • Action: Recite "Master of the world..." prayer.
                  • Action: Return to original prayer location.
                  • Action: Resume prayer at point of interruption.
        • Type B: Sneeze
          • Origin Identified:
            • From Below (interpreted as gas): Treat as Type A: Passing Gas.
            • From Above (actual sneeze):
              • Significance: Considered a good sign (positive system signal).
              • Action: Continue prayer without interruption or special procedure.
    • NO:
      • Continue Amidah Prayer.

• Interruption Logic (for non-biological, but related events like King, Snake, Ox):

  • If Interruption Occurred:
    • Calculate Delay: Was the delay long enough to finish the entire Amidah prayer?
      • YES:
        • Recovery: Restart Amidah from the beginning.
      • NO:
        • Recovery: Return to the beginning of the interrupted blessing.
        • Exception: If interrupted in the first three blessings, restart from the beginning.
        • Exception: If interrupted in the latter three blessings, return to the "R'tzei" blessing.
  • If Interruption was Conversation: Treat as a standard interruption with the above recovery logic.
  • If Interruption was for Kaddish/Kedusha: Do NOT interrupt. Remain silent; focus on prayer leader.
  • Post-Amidah, Pre-"Elokai, Netzor": Allowed to answer Kaddish, Kedusha, Barchu.

This flow model highlights the conditional logic and state management required to handle these prayer interrupts. It's all about state transitions and error recovery.

Two Implementations: Rishonim vs. Acharonim as Algorithm A vs. Algorithm B

Let's compare how the early authorities (Rishonim) and later authorities (Acharonim) might be seen as implementing slightly different algorithms for handling these prayer interrupts, particularly the nuanced case of passing gas. Think of Algorithm A (Rishonim) as a more foundational, less optimized version, and Algorithm B (Acharonim) as a refined, context-aware update.

Algorithm A: The Rishonim's Foundational Protocol (Focus on Core Principles)

The Rishonim, like the Baal HaTanya (though he's an Acharon, his approach often reflects earlier principles) and the Ri, lay down the fundamental rules. Their code is generally more direct, focused on the primary directive of prayer continuity and avoiding significant disruptions.

Core Logic (Algorithm A):

1. Input: Prayer session, Biological Event.
2. Event Type Check:
   • If event_type == "sneeze_above":
     • return STATUS_CONTINUE_PRAYER (Good sign, no action needed).
   • If event_type == "gas_below":
     • Context Check: is_public_congregation = (prayer_environment == "congregation")
     • If NOT is_public_congregation (Praying at home):
       • Urgency Check: is_uncontainable_urge = (discomfort_level > HIGH_THRESHOLD)
       • If is_uncontainable_urge:
         • Action Sequence:
           • move_distance(4_cubits, direction="back")
           • execute_event("pass_gas")
           • wait_for_smell_dissipation(self=True)
           • recite_prayer("Master_of_the_world")
           • return_to_original_position()
           • resume_prayer_at_interrupted_point()
         • return STATUS_RECOVERED
       • Else (Gas released, not uncontainable):
         • Action Sequence:
           • wait_for_smell_dissipation(self=True)
           • resume_prayer_at_interrupted_point()
         • return STATUS_RECOVERED
     • Else (is_public_congregation):
       • Social Constraint Check: is_high_embarrassment = (social_context == "congregation" AND direct_action_causes_embarrassment)
       • If is_high_embarrassment:
         • Action Sequence:
           • wait_for_smell_dissipation(self=True)
           • resume_prayer_at_interrupted_point()
         • return STATUS_RECOVERED
       • Else (Embarrassment manageable, or private prayer context):
         • (This branch is less explicitly defined for the congregation but implies a potential return to private protocols if feasible, though the Gloss leans heavily towards minimizing public disruption).
         • move_distance(4_cubits, direction="back")
         • execute_event("pass_gas")
         • wait_for_smell_dissipation(self=True)
         • recite_prayer("Master_of_the_world")
         • return_to_original_position()
         • resume_prayer_at_interrupted_point()
         • return STATUS_RECOVERED
3. Return: STATUS_CONTINUE_PRAYER or STATUS_RECOVERED.

Key Characteristics of Algorithm A:

• Directives: Clear, often binary choices.
• State Variables: Primarily focuses on prayer_environment and event_type.
• Recovery: Emphasizes physical movement and specific vocalizations ("Master of the world...") as core recovery modules.
• Efficiency: Might be less concerned with subtle social nuances, prioritizing the halachic principle. The "walking 4 cubits" is a concrete, defined action.
• Magen Avraham's Input: The Magen Avraham, while a later commentator, often synthesizes and clarifies Rishonim. His commentary on 103:3, about the "walking" not being a significant interruption compared to speech, reflects this foundational approach. He sees the "urge" as a state that already "interrupts" the prayer's flow, making further action (like walking) a permissible deviation.
• Ba'er Hetev's Input: His commentary on 103:2 suggests internal contemplation ("יהרהר בלבו") as an alternative to external vocalization if the "Master of the world" prayer is too disruptive or difficult. This hints at a slightly more flexible interpretation within the foundational framework.

Algorithm B: The Acharonim's Refined Protocol (Context-Aware Optimization)

The Acharonim, especially those commenting on the Shulchan Arukh and citing the Terumat HaDeshen, introduce more sophisticated contextual awareness and optimization. They refine the algorithm to be more efficient and socially intelligent, especially in the context of a public prayer service.

Core Logic (Algorithm B - Optimized):

1. Input: Prayer session, Biological Event, Social Context.
2. Event Type Check:
   • If event_type == "sneeze_above":
     • return STATUS_CONTINUE_PRAYER (Good sign, no action needed).
   • If event_type == "gas_below":
     • Context Check: is_public_congregation = (prayer_environment == "congregation")
     • If is_public_congregation:
       • Social Constraint Check: is_high_embarrassment = (social_context == "congregation" AND direct_action_causes_embarrassment)
       • If is_high_embarrassment:
         • Action Sequence:
           • wait_for_smell_dissipation(self=True) (Minimal movement, focus on self)
           • resume_prayer_at_interrupted_point()
         • return STATUS_RECOVERED
       • Else (Embarrassment manageable - private prayer context):
         • (This branch aligns with the home-based protocol)
         • move_distance(4_cubits, direction="back")
         • execute_event("pass_gas")
         • wait_for_smell_dissipation(self=True)
         • recite_prayer("Master_of_the_world")
         • return_to_original_position()
         • resume_prayer_at_interrupted_point()
         • return STATUS_RECOVERED
     • Else (NOT is_public_congregation - Praying at home):
       • Urgency Check: is_uncontainable_urge = (discomfort_level > HIGH_THRESHOLD)
       • If is_uncontainable_urge:
         • Action Sequence:
           • move_distance(4_cubits, direction="back")
           • execute_event("pass_gas")
           • wait_for_smell_dissipation(self=True)
           • recite_prayer("Master_of_the_world")
           • return_to_original_position()
           • resume_prayer_at_interrupted_point()
         • return STATUS_RECOVERED
       • Else (Gas released, not uncontainable):
         • Action Sequence:
           • wait_for_smell_dissipation(self=True)
           • resume_prayer_at_interrupted_point()
         • return STATUS_RECOVERED
3. Return: STATUS_CONTINUE_PRAYER or STATUS_RECOVERED.

Key Characteristics of Algorithm B:

• Contextual Prioritization: The is_public_congregation flag is a primary branching point, heavily influencing subsequent logic. This reflects the "And such is how we practice" of the Terumat HaDeshen, as cited in the gloss.
• Social Optimization: Explicitly encodes the "great embarrassment" factor as a condition to modify the standard procedure. The gloss acts as a patch that overrides parts of the core logic in specific environments.
• Efficiency: Minimizes unnecessary actions (like reciting the "Master of the world" prayer or excessive movement) when social factors dictate.
• Refinement: Integrates and clarifies earlier rulings, creating a more cohesive and practical system. The Mishnah Berurah's commentary on 103:3, mentioning the potential need to adjust tefillin if praying with them, shows a deeper engagement with the physical implications and practicalities.
• Terumat HaDeshen's Input: This is the crucial library for Algorithm B's refinement. It introduces the congregation parameter and its impact on the embarrassment variable, leading to a simplified, less disruptive public protocol.

Algorithmic Comparison: A Tale of Two Compilers

Feature	Algorithm A (Rishonim)	Algorithm B (Acharonim)
Primary Focus	Core halachic principles, direct action.	Contextual adaptation, social efficiency, refined practice.
Key Variable	Event type, basic environment (home/elsewhere).	Event type, environment (congregation), social embarrassment.
Public Protocol	Less differentiated; tends towards home protocol.	Heavily modified; minimizes disruption, vocalization, movement.
Recovery Module	Standardized: walk, pass, wait, recite, return, resume.	Dynamic: adapts based on social context.
"Master of World"	Standard recovery step when possible.	Conditional; omitted in high-embarrassment congregation.
Refinement Source	Direct textual interpretation.	Integration of glosses, later commentaries (Terumat HaDeshen).
Analogy	Assembly Language - fundamental, powerful, less abstract.	Compiled, Optimized Code - more abstract, context-aware, efficient.

The Acharonim's approach is akin to a software engineer adding conditional compilation flags and environment-specific configurations to a base library. They recognize that the same core functionality needs to behave differently based on the deployment environment (prayer hall vs. home).

Edge Cases – Inputs That Break Naïve Logic

Let's explore scenarios where a simple, unrefined "if-then-else" logic would fail, requiring the more sophisticated algorithms we've outlined. These are like unit tests designed to expose bugs in simplistic implementations.

Edge Case 1: The "Silent Reactor" in a Packed Synagogue

• Input Scenario: A person is praying the Amidah in a packed synagogue during Rosh Hashanah. They experience a gas emission, but it is completely silent and odorless.
• Naïve Logic Failure: A basic algorithm might check for smell_dissipates and embarrassment_from_noise. If there's no smell and no noise, it might incorrectly assume no disruption occurred or that the user can simply continue without any specific action. It might even prompt the user to wait for a smell that will never materialize.
• Corrected Logic (Algorithm B):
  1. Event Type: gas_below detected.
  2. Context: is_public_congregation = TRUE.
  3. Social Constraint Check: is_high_embarrassment. Even though there's no smell/noise, the act of passing gas, even silently, in a packed synagogue carries potential social implications if it were to become known or if the person believes it might be detected. The gloss states, "one does not need to distance oneself at all backwards, and one also shouldn't say the 'Master [of the worlds]...'" and "And such is how we practice." This implies that in a public setting, the priority is to avoid any action that draws attention or could cause embarrassment, even if the physical manifestation is minimal. The principle of "it is revealed and known before You our disgrace and shame" (from the prayer) is meant for a private confession of the bodily event, not for public display.
  4. Expected Output: The user should simply wait_for_smell_dissipation(self=True) (which in this case might be instantaneous or involve a quick internal check) and then resume_prayer_at_interrupted_point(). No physical movement, no special prayer, and no need to wait for an external smell. The "embarrassment" factor, even if only perceived, dictates the minimal intervention. The core principle is to avoid any action that could be perceived as a significant interruption or cause discomfort to others.

Edge Case 2: The "Accidental Interrupter" and the "Fast Praying" Parameter

• Input Scenario: A person is praying the Amidah on a busy road. Suddenly, a large, angry-looking snake coils around their ankle. They manage to shake it off and resume prayer within what they perceive to be a very short time, much less than the time it would take to recite the entire Amidah. However, their prayer speed is exceptionally slow (e.g., they are a very deliberate, slow reader of prayers).
• Naïve Logic Failure: A basic system might only check interruption_occurred = TRUE and delay_time < estimated_amidah_completion_time. If the user subjectively feels the delay was short, they might resume from the interrupted blessing. This ignores the crucial detail about calculating the time based on the speed of the one reading.
• Corrected Logic (Algorithm B, incorporating 104:1):
  1. Event: Dangerous animal (snake) encountered.
  2. Action: Interrupt prayer to deal with danger (snake).
  3. Recovery Protocol Triggered.
  4. Crucial Calculation: The rule states, "if one delayed long enough to finish all of it [i.e. the Amidah prayer], one must return to the beginning." This time is calculated "based on the speed of] the one reading (i.e. praying)."
  5. Let's say the "standard" time to recite the Amidah is 10 minutes. However, this particular individual's prayer speed is very slow, and the actual time it would take them to complete the Amidah is, say, 20 minutes.
  6. The time taken to deal with the snake, including the physical action and any momentary shock, was 15 minutes.
  7. Comparison: actual_delay (15 mins) > user's_personal_amidah_completion_time (20 mins) is FALSE.
  8. Correction: The rule is not about the standard time, but their time. So, actual_delay (15 mins) < user's_personal_amidah_completion_time (20 mins) is TRUE.
  9. Expected Output: According to the rule "if not, then one returns to the beginning of the blessing that one interrupted." The user should resume from the blessing they were in when the snake appeared. The fact that it was a snake is important for allowing the interruption, but the consequence of that interruption on prayer continuity is dictated by the time calculation. The "angry snake" is a high-priority interrupt, but the prayer system still needs to recover gracefully.

These edge cases demonstrate that a robust system requires more than just simple event detection. It needs nuanced contextual analysis, dynamic parameterization (like prayer speed), and a clear understanding of prioritization rules.

Refactor – One Minimal Change That Clarifies the Rule

Our goal is to achieve greater clarity and reduce ambiguity in the system's operational logic. The most impactful refactor would involve explicitly defining the "Interruption Point Threshold" (IPT) based on the "Personal Prayer Speed" (PPS).

Current Ambiguity: The rule for restarting the Amidah after an interruption is tied to "delaying long enough to finish all of it." This is quantified by the speed of the one praying. However, the trigger for this calculation isn't always explicitly tied to how the interruption occurred.

Proposed Refactor: Introduce a clear, quantifiable definition for when an interruption necessitates a full restart versus resuming from the interrupted blessing.

Minimal Change:

Add a specific parameter to the interruption handling module:

• New Parameter: Interruption Point Threshold (IPT)

  • Definition: IPT = Personal Prayer Speed (PPS) * 1.0 (i.e., the time it takes for the individual to recite the entire Amidah).

• Refined Rule Logic:

  • If interruption_duration > IPT:
    • restart_amidah_from_beginning()
  • Else (interruption_duration <= IPT):
    • If interrupted_blessing_index <= 2 (first three blessings):
      • restart_amidah_from_beginning()
    • Else if interrupted_blessing_index >= 15 (last three blessings):
      • resume_prayer_at_blessing("R'tzei")
    • Else:
      • resume_prayer_at_interrupted_blessing()

Impact of Refactor:

This refactor clarifies that the decision to restart the entire Amidah is always a function of the individual's personal prayer speed. It removes any potential misinterpretation that "long enough" might refer to a general, standardized prayer speed. The IPT becomes a dynamic, user-specific configuration parameter.

Consider the example of the snake again. If the user's PPS is 20 minutes, and they took 15 minutes to deal with the snake, 15 <= 20 is true. Therefore, they resume from the interrupted blessing. If, however, they took 25 minutes to deal with the snake, 25 > 20 is true, and they must restart from the beginning. This makes the system's behavior predictable and consistently applicable across different prayer speeds. It's like setting a clear timeout value for a network request based on user-defined latency expectations.

Takeaway + Citations

Our deep dive into Shulchan Arukh 103:2-104:1 reveals a sophisticated set of protocols for handling biological and external interrupts during the Amidah prayer. This isn't just about avoiding embarrassment; it's about maintaining the integrity of a critical spiritual process. We've seen how the text functions like an operating system with built-in exception handling:

• Event Detection: Identifying biological interrupts (gas, sneeze) and external threats (king, snake, ox).
• Contextual Logic: Differentiating behavior based on environment (home vs. congregation).
• Severity Assessment: Categorizing events (sneeze vs. gas, dangerous vs. non-dangerous).
• Recovery Procedures: Implementing specific actions, from physical movement and vocalizations to simple waiting.
• State Management: Tracking prayer progress and determining restart points based on interruption duration and location.

The evolution from the foundational principles of Rishonim (Algorithm A) to the context-aware, socially optimized protocols of the Acharonim (Algorithm B) mirrors the development of robust software systems. We move from raw, powerful commands to intelligent, adaptive modules that consider user experience and environmental factors. The "glosses" and later commentaries act like patches and feature updates, enhancing the core functionality.

Ultimately, these laws teach us the importance of mindful execution and graceful recovery. Even when faced with unexpected "bugs" in our physical or external environment, the system of Jewish law provides a framework to return to our intended spiritual task with minimal corruption, always striving for the most efficient and appropriate path back to connection. It's a testament to the timeless wisdom embedded in the Halakha, designed to guide us through the complexities of life with precision and reverence.

Citations

• Shulchan Arukh, Orach Chayim 103:2-104:1: https://www.sefaria.org/Shulchan_Arukh%2C_Orach_Chayim_103%3A2-104%3A1
• Terumat HaDeshen Siman 16: (Cited within the Shulchan Arukh text)
• Ri (on Berachot 30b): (Cited within the Shulchan Arukh text)
• Rashb"a in Siman 185: (Cited within the Shulchan Arukh text)
• Magen Avraham on Shulchan Arukh, Orach Chayim 103:2: https://www.sefaria.org/Magen_Avraham%2C_Orach_Chayim_103.2
• Magen Avraham on Shulchan Arukh, Orach Chayim 103:3: https://www.sefaria.org/Magen_Avraham%2C_Orach_Chayim_103.3
• Magen Avraham on Shulchan Arukh, Orach Chayim 103:4: https://www.sefaria.org/Magen_Avraham%2C_Orach_Chayim_103.4
• Magen Avraham on Shulchan Arukh, Orach Chayim 103:5: https://www.sefaria.org/Magen_Avraham%2C_Orach_Chayim_103.5
• Ba'er Hetev on Shulchan Arukh, Orach Chayim 103:2: https://www.sefaria.org/Ba%27er_Hetev%2C_Orach_Chayim_103.2
• Mishnah Berurah on Shulchan Arukh, Orach Chayim 103:3: https://www.sefaria.org/Mishnah_Berurah%2C_Orach_Chayim_103.3
• Mishnah Berurah on Shulchan Arukh, Orach Chayim 103:4: https://www.sefaria.org/Mishnah_Berurah%2C_Orach_Chayim_103.4
• Mishnah Berurah on Shulchan Arukh, Orach Chayim 103:5: https://www.sefaria.org/Mishnah_Berurah%2C_Orach_Chayim_103.5