Daily Rambam Accelerated · Expert – Beit Midrash Analysis · Standard
Mishneh Torah, Sacrificial Procedure 7-9
Sugya Map
The halachic landscape of Rambam’s Mishneh Torah, Hilchot Ma'aseh HaKorbanot (Sacrificial Procedure) Chapters 7–9, centers on the post-slaughter processing of offerings: the Chatat (sin-offering), the Asham (guilt-offering), and the Shelamim (peace-offering). Far from being mere technical rubrics, these chapters serve as the primary loci for analyzing the metaphysical boundaries of the Azarah (Temple Courtyard), the transmission of consecration through physical contact, and the dual vectors of avodah (temple service) split between the gavra (the human agent) and the cheftza (the physical sacrifice).
Core Halachic Issues
- The Spatial Topography of Destruction: The categorization of the three loci of burning (Azarah, Birah, and the Ash-pile) and how the disqualification of a sacrifice alters its metaphysical coordinates.
- The Mechanics of Blood-Garment Consecration: The scriptural mandate of beged she-huzah alav dam (a garment upon which sin-offering blood sputtered) and the parameters of its mandatory purging within the Azarah.
- The Physics of Taste and Sacrificial Absorption: The requirements of merikah u-shetiphah (scouring and rinsing) for metal vessels and the breaking of earthenware vessels (shevirat kli cheres) used for cooking holy meats.
- The Dynamics of Tenufah (Waving): The cooperative physical actions of the priest and the owner in elevating the sacrificial portions, and the exact dimensional and agricultural specifications of the accompanying breads.
[SACRIFICIAL SYSTEM (Ma'aseh HaKorbanot 7-9)]
│
┌────────────────────────────┼────────────────────────────┐
▼ ▼ ▼
[SPATIAL DYNAMICS] [CONSECRATION & PURGING] [ELEVATION DYNAMICS]
• Chatat Eaten vs. Burnt • Sputtered Blood (8:1) • Tenufah (9:5-9)
• 3 Loci of Burning (7:3) • Earthenware/Metal (8:11) • Priest-Owner Synergy
• Southwest Corner (7:10) • Touch Consecration (8:16) • Bread Specifications
Nafka Mina (Practical & Conceptual Ramifications)
- The Ontological Status of Consecrated Taste (Ta'am ke-Ikkar): Does the taste absorbed in a vessel acquire the actual identity of notar (sacrificial meat left past its time limit), or is it merely a secondary trace that triggers a preventative cleansing? This dictates whether non-sin-offerings require scouring under biblical or rabbinic mandates.
- The Definition of "Garment" (Shem Beged): Does tearing a garment to rid it of tuma'ah (impurity) destroy its identity for the mitzvah of blood-washing? If so, the washing is invalidated; if not, the physical material remains consecrated.
- The Nature of Tenufah: Is waving an act of offering to the Creator (a gavra obligation of gratitude) or an objective matir (permitting mechanism) that structurally validates the eimorim (sacrificial fats) for the altar?
Primary Sources
- Torah: Leviticus 4:1-35, Leviticus 6:19-23, Leviticus 7:1-38.
- Talmud: Zevachim 93a–98b (concerning sputtered blood and vessel purging); Menachot 61a–62b (concerning the physical mechanics of tenufah); Zevachim 63a (concerning the southwest corner of the altar).
Full Experience in the App
Listen. Chat. Go deeper.
Audio playback, interactive chevruta, Hebrew tools, and every daily learning track — only in Derekh Learning.
Text Snapshot
To understand the Rambam’s conceptual framework, we must examine the precise language of the text alongside the annotations of the Steinsaltz commentary, which ground the halachot in their primary talmudic and biblical sources.
Text 1: The Standard Procedure of the Chatat
Rambam writes in Ma'aseh HaKorbanot 7:1:
"כיצד חטאות הנאכלות מביאות? שוחט ונותן הדם כמו שבארנו..." (How are the sin-offerings which are eaten brought? One slaughters [the animal] and sprinkles its blood in the manner described...)
Steinsaltz Commentary Unpacked
- כְּמִצְוָתָן הָאֲמוּרָה בַּתּוֹרָה: The Steinsaltz commentary notes: "ויקרא פרקים ד-ה" (Leviticus Chapters 4–5), establishing that the positive commandment to offer the Chatat is a singular, unified mitzvah despite the variance in animal types.[^1]
- שׁוֹחֵט וְנוֹתֵן הַדָּם כְּמוֹ שֶׁבֵּאַרְנוּ: Steinsaltz clarifies: "שחיטה בצפון המזבח (לעיל ה,ב-ג), ונתינת הדם על ארבע קרנות המזבח למעלה (לעיל ה,ז)" (Slaughtering must occur in the northern section of the Courtyard, and the application of blood must be on the four upper horns of the altar). This highlights the spatial contrast with other sacrifices: the Chatat is uniquely elevated, requiring the priest to climb the ramp and apply the blood to the upper half of the altar.[^2]
- וּמַפְרִישׁ הָאֵמוּרִין: "מוציא מהבהמה את החלקים שקרבים על המזבח (לעיל א,יח)" (He extracts from the beast the specific fats and organs designated for the altar pyre).
- וּמוֹלְחָן: "כדין כל הקרב על המזבח (הלכות איסורי מזבח ה,יא)" (In accordance with the universal law that all offerings on the altar must be salted).
- וְזוֹרְקָן עַל גַּבֵּי הָאִשִּׁים: "על מערכת האש שבמזבח" (Onto the wood pile arranged on the altar).
- וְאִם רָצָה לִתֵּן אֶת הָאֵמוּרִין בִּכְלִי כְּשֶׁמַּשְׁלִיכָן לַמִּזְבֵּחַ נוֹתֵן: "ואינו חייב להוליכם ולהשליכם בידו" (He is not obligated to carry and throw them by hand; a sacred vessel may act as an intermediary, which does not constitute an invalidating interposition).
- נֶאֱכָל לְזִכְרֵי כְּהֻנָּה בָּעֲזָרָה: "לקמן י,ג" (Eaten only by male priests within the sacred courtyard, limiting consumption both by gender and geography).
Text 2: The Southwest Corner and Spatial Economy
Rambam writes in Ma'aseh HaKorbanot 7:10:
"קרן דרומית מערבית של מזבח היתה משמשת לשלשה דברים בחציה העליון ולשלשה דברים בחציה התחתון..." (The upper half of the southwest corner of the altar would serve three purposes and the lower half would serve three purposes...)
[ALTAR SOUTHWEST CORNER]
│
┌────────────────────────┴────────────────────────┐
▼ ▼
[UPPER HALF] [LOWER HALF]
1. Water Libation (Sukkot) 1. Melikah of Bird Chatat
2. Wine Libation (Sukkot) 2. Approaching with Meal-Offerings
3. Overflow Bird Burnt-Offerings 3. Pouring of Blood Remainders
Steinsaltz Commentary Unpacked
- קֶרֶן דְּרוֹמִית מַעֲרָבִית וכו': "הזווית הדרומית מערבית של המזבח בחצי העליון (מעל חוט הסקרא), ובחצי התחתון" (The southwestern corner of the altar, divided by the red line (chut ha-sikra) that girdled the middle of the altar).
This architectural division serves as a physical boundary for blood applications: animal Chatat blood must be applied above the line, while bird Chatat blood (melikat chatat ha-of) must be applied below the line. The southwest corner acts as a spatial junction where the most elevated services and the lowliest applications (such as draining remaining blood) meet.
Readings
The conceptual mechanics of Chapters 8 and 9 invite deep analysis from the Rishonim and Acharonim. We will examine three major theoretical disputes (chakirot) that define the inner logic of these laws.
Reading A: The Nature of the Washing Obligation (Beged She-Huzah)
In Ma'aseh HaKorbanot 8:1, the Rambam codifies the law of a garment stained by sputtered Chatat blood:
$$\text{Sputtered Blood} + \text{Garment} \xrightarrow{\text{Before Sprinkling}} \text{Mandatory Washing in Azarah}$$
If the blood of an animal Chatat is received in a sacred vessel and then sputters onto a garment before the sprinkling on the altar has occurred, the garment must be washed within the Azarah.[^3]
The Brisker Inquiry (Rav Chaim Soloveitchik)
Is the obligation to wash the garment a tikkun (rectification) of the garment, which has contracted an anomalous state of holiness, or is it an avodah (service) performed on the blood itself?
[THE NATURE OF OBLIGATORY WASHING]
│
┌───────────────────────────┴───────────────────────────┐
▼ ▼
[TIKKUN BEGED] [AVODAT DAM]
• Focus: The Garment (Cheftza) • Focus: The Blood (Cheftza)
• Goal: Purging absorbed holiness • Goal: Sacred disposal of blood
• Outcome: Disqualification cancels • Outcome: Disqualification requires
the obligation. washing (Rashi).
- The Garment-Centric View (Tikkun Beged): The sputtering of the blood onto an external object is a form of displacement. The garment absorbs the physical essence of the sacrifice, and must be purged of this misplaced holiness within the Temple Courtyard.
- The Blood-Centric View (Avodat Dam): The washing is a form of sacred disposal. The blood of a Chatat cannot be left to degrade on a mundane material; the act of washing it off in the Azarah is a continuation of the blood rites (avodat ha-dam).
The Rishonim Dispute
Rashi's Position: Rashi in Zevachim 93b explains that even if the Chatat blood becomes disqualified after sputtering, the obligation to wash remains if there was a "moment of fitness" (sha'at kosher). This suggests that once the blood lands on the garment, it initiates an independent obligation of disposal (avodat dam).
Rambam's Position: Rambam writes in 8:3:
"חטאת שנפסלה--אין דמה טעון כיבוס..." (When a sin-offering was disqualified, its blood need not be washed...)[^4]
For the Rambam, a disqualified sacrifice is completely exempt from the washing requirement. This indicates that the obligation is not a general rule of blood disposal, but is bound to the active halachic status of the offering. The washing is a tikkun of a garment that contains active, valid sacrificial blood. If the sacrifice is disqualified, the blood loses its holy status, and the garment no longer requires rectification.
Reading B: The Alchemy of Absorption—Earthenware vs. Metal
In Ma'aseh HaKorbanot 8:11, the Rambam addresses the vessels used to cook sacrificial meat:
"כלי חרס שבישל בו חטאת הנאכלת--ישבר בעזרה... וכלי נחושת שבישל בו--ימרק וישטף במים בעזרה..." (An earthenware vessel in which a sin-offering... was cooked must be broken... A metal vessel... must be cleansed and rinsed...)[^5]
[VESSEL PURGING SYSTEM (8:11)]
│
┌─────────────────────────┴─────────────────────────┐
▼ ▼
[EARTHENWARE (Cheres)] [METAL (Nechoshet)]
• Cannot release absorbed taste • Can release absorbed taste
• Must be broken in Azarah • Must be scoured (hot) & rinsed (cold)
• Absolute destruction (Gezerat Hakatuv) • Purging of absorbed flavor
The Conceptual Chashash (Concern): Is it Notar or a Chok?
Why does the Torah require the destruction of earthenware and the purging of copper?
The Rashi/Ra'avad Paradigm (The Notar Hypothesis): The meat of the Chatat is absorbed into the walls of the vessel (baliah). Once the permitted time for eating the offering (one day and the following night) passes, the absorbed taste (ta'am) becomes notar (leftover sacrificial food, which is forbidden). Because earthenware cannot release its absorbed taste through boiling (eino yotzei mi-dafi le'olam), the vessel contains permanent, irreversible notar and must be destroyed. Metal, which can release its absorption, is purged to remove the notar.
The Rambam’s Paradigm (The Structural Avodah Hypothesis): In Ma'aseh HaKorbanot 8:14, the Rambam rules:
"בישל בה פעמיים ושלוש... ממרק ושוטף בסוף זמן האכילה" (One may cook in a utensil... a second and third time immediately... The requirement to wash... applies only at the conclusion of the time permitted to partake...)[^6]
If the issue were simply the physical presence of notar, cooking a second time before the time limit has passed should be permitted without issue, but the vessel would still need to be purged immediately once the time limit is reached.
However, the Rambam views merikah u-shetiphah (scouring and rinsing) not merely as a way to remove forbidden tastes, but as a formal concluding rite of the sacrificial service. The cooking of the sacrifice transfers its holy status to the vessel itself (yikdash). Once the eating period ends, this vessel-bound holiness must be resolved—either through destruction (for earthenware) or a formal water rite (for metal). It is a structural requirement of the Temple service, not just a standard law of dietary kashrut.
Reading C: The Mechanics of Tenufah (Waving)
In Ma'aseh HaKorbanot 9:5–9, the Rambam details the waving of the Shelamim (peace-offerings) and the Todah (thanksgiving offering):
"הבעלים מניח אימורין על ידיו, וחזה ושוק... וכהן מניח ידיו תחת ידי הבעלים ומניף..." (The owner places the emorim on his hands, with the breast and thigh... and the priest places his hands beneath the hands of the owner and performs waving...)[^7]
[THE DYNAMICS OF TENUFAH]
│
┌────────────────────────┴────────────────────────┐
▼ ▼
[GAVRA ORIENTED] [CHEFTZA ORIENTED]
• Focus: The Agent (Owner/Priest) • Focus: The Object (Offering)
• Action: Expression of surrender • Action: Metaphysical transformation
• Rule: Excludes women (except Sotah/Nazir) • Rule: Essential for altar validation
The Brisker Chakirah: Gavra vs. Cheftza in Tenufah
Is the physical act of waving (tenufah) a duty of the person (chovat gavra) to express gratitude and surrender to God, or is it an objective transformation of the sacrificial parts (chovat cheftza) required to validate them for the altar?
- The Person-Oriented View (Chovat Gavra): Waving is an act of dedication by the owner. This explains why the owner’s hands must be directly under the offering, with the priest’s hands supporting them from below. The owner is the primary agent of the wave.
- The Object-Oriented View (Chovat Cheftza): Waving is an essential step in preparing the sacrifice. Without it, the eimorim cannot be offered on the altar.
Resolving the Role of Women in Tenufah
Rambam rules in Ma'aseh HaKorbanot 9:14:
"האשה כיון שהיא מביאה קרבן--אינה מניפה, אלא הכהן מניף..." (When a woman is the one bringing a sacrifice, she does not perform waving. The priest must perform that rite...)[^8]
If tenufah were strictly a personal obligation of the owner (chovat gavra), a female owner should wave her own offering, just as she performs semichah (resting of hands) according to some authorities, or she should be exempt from the requirement entirely.
However, the Rambam rules that the waving must still occur, but it is performed by the priest on her behalf. This proves that tenufah is an objective requirement of the sacrifice (chovat cheftza). While the ideal performance combines the owner and the priest, the physical waving of the offering remains necessary to validate the sacrifice, even when the owner cannot personally participate.
Friction
The Kushya: The Paradox of the Torn Garment
In Ma'aseh HaKorbanot 8:19, the Rambam addresses a complex scenario:
$$\text{Sputtered Garment} \xrightarrow{\text{Taken Outside Azarah}} \text{Becomes Impure} \xrightarrow{\text{How to Return & Wash?}} \text{The Dilemma}$$
If a garment with sputtered Chatat blood is taken outside the Temple Courtyard (Azarah) and becomes ritually impure (tamei), we face a conflict of laws:
- The garment must be washed inside the Azarah (Leviticus 6:20).
- An impure object cannot be brought into the Azarah (due to the prohibition of tuma'at mikdash).
To resolve this, the Rambam writes:
"קורעו עד שיטהר... ומניח בו כדי מטפחת--מפני שהבגד טעון כיבוס" (He should tear it so that it will become pure... He must leave intact a portion of the garment the size of a handkerchief, for [the verse] speaks of a "garment" [requiring washing]...)[^9]
[PARADOX OF THE TORN GARMENT]
│
┌─────────────────────────┴─────────────────────────┐
▼ ▼
[TUMA'AH LAW] [KIBUS LAW]
• Tear majority of garment • Must wash a "garment" (Beged)
• Nullifies "Kli" status • Requires minimum size (handkerchief)
• Result: Ritually Pure • Result: Valid for Kibbus
The Core Difficulty
This solution presents a conceptual problem. To rid the garment of its impurity (tuma'ah), it must be torn until it loses its status as a functional utensil or garment (shem beged). Yet, to fulfill the mitzvah of washing, the Torah explicitly requires washing a garment (beged).
If the tearing is comprehensive enough to nullify the garment's identity for the laws of impurity, how can it still be considered a "garment" for the laws of washing? The two requirements appear to be mutually exclusive:
$$\text{Torn to Purify} \implies \text{No longer a "Beged" (No Kibbus)}$$ $$\text{Intact for Kibbus} \implies \text{Still "Tamei" (Cannot enter Azarah)}$$
The Terutzim
Terutz 1: The Dual Definition of "Beged" (The Griz Soloveitchik)
We can resolve this difficulty by distinguishing between two different definitions of a "garment" (shem beged) in halacha:
- The Functional Definition (for Tuma'ah): For an object to contract or retain impurity, it must be a functional, completed utensil or garment (kli). Tearing the majority of the garment destroys this functional status, which immediately purifies the material.
- The Material Definition (for Kibbus): For the laws of washing sputtered blood, the requirement does not depend on the object being a fully functional garment. It only requires that the blood be washed from a woven textile of a significant size.
The minimum size for a textile to be called a garment in this context is the size of a "handkerchief" (ki-mdefat). By tearing the garment to remove its impurity while keeping a piece of this size intact, we satisfy both laws: the functional garment is destroyed (removing the impurity), but a sufficient piece of textile remains to fulfill the washing requirement.
Terutz 2: The Principle of Retrospective Identity (She'ar Beged)
An alternative solution, suggested by the Or Sameach, focuses on the relationship between the torn pieces and the original garment.^10
When the Torah states "that which it has been spewed upon must be washed," the obligation of kibbus attaches directly to the specific fibers that absorbed the blood. Even if the larger garment is torn to remove its impurity, those specific fibers do not lose their history.
As long as the portion containing the blood remains intact at the minimum size of a handkerchief, it retains a retrospective identity as the garment that was originally stained. The act of tearing removes the general status of impurity from the object, but it does not erase the specific obligation of washing that was already bound to the stained fabric.
Intertext
The laws of Temple purification and vessel purging in Ma'aseh HaKorbanot serve as the conceptual foundation for the laws of dietary koshering (kashering) in daily life.
The Talmudic Source: Zevachim 97a
The Talmud in Zevachim 97a derives the rules for purging absorbed tastes from the biblical requirements of merikah u-shetiphah (scouring and rinsing) found in Leviticus 6:21:
$$\text{Temple Scouring/Rinsing} \xrightarrow{\text{Baliah Principle}} \text{Mundane Koshering (Hag'alah)}$$
This passage establishes the fundamental principle of Baliah (absorption) and Plitah (extraction):
$$\text{Taste Absorption (Ta'am)} \equiv \text{Physical Meat (Mamashut)}$$
The taste of food absorbed into the walls of a vessel carries the same halachic status as the food itself. This principle is directly applied to the laws of daily kashrut.
The Halachic Transition: Shulchan Aruch, Yoreh Deah 121
The Shulchan Aruch adapts these Temple requirements into the practical laws of koshering everyday utensils:
| Temple Law (Ma'aseh HaKorbanot) | Mundane Law (Shulchan Aruch, Yoreh Deah) | Halachic Concept |
|---|---|---|
| Earthenware (Cheres): Must be broken; cannot be purged of sacrificial taste.[^11] | Earthenware (Cheres): Cannot be kashered; must be set aside or discarded if used for non-kosher.[^12] | Eino Yotzei Mi-Dafi: Earthenware permanently retains absorbed substances. |
| Metal Vessels (Nechoshet): Purged with hot water (merikah) and rinsed with cold water (shetiphah).[^13] | Metal Vessels: Koshered through boiling water (hag'alah) and rinsed with cold water.[^14] | Ke-Vole'o Kach Polto: Utensils release absorbed tastes in the same manner they were absorbed. |
The Conceptual Divergence: Hag'alah vs. Merikah
While everyday koshering is modeled after the Temple service, there is a key conceptual difference between them:
- Mundane Koshering (Hag'alah): This is a physical process of extraction. The goal is to remove the absorbed non-kosher taste from the vessel. Therefore, the water must be boiling to ensure the taste is fully extracted (ke-vole'o kach polto).
- Temple Purging (Merikah u-Shetiphah): As noted by the Rogatchover Gaon, Temple purging is a formal ritual decree (gezerat hakatuv).[^15] Even if a vessel is physically clean and contains no remaining taste, it must still undergo the formal process of scouring and rinsing at the end of the eating period.
This explains why the Rambam requires cold water for the final rinse (shetiphah). In everyday koshering, cold water is used simply to cool the vessel and stop the cooking process. In the Temple, the cold water rinse is an intrinsic part of the purification rite itself, showing that these laws are not just about hygiene, but about maintaining the ritual order of the Sanctuary.
Psak/Practice
The laws of sacrificial procedure and vessel purification illustrate how the Rambam balances strict ritual requirements with practical considerations.
Meta-Psak Heuristic: "Ein Aniyut Be-Makom Ashirut" vs. "Bal Tashchit"
The Temple service operates under the general principle:
$$\text{Ein Aniyut Be-Makom Ashirut (No Poverty in the Place of Wealth)}$$
This principle suggests that the Temple should always use the finest and most valuable materials, without regard for cost. However, this is balanced by the prohibition of Bal Tashchit (wanton destruction) and the need for resource conservation.
We see this balance in the laws of vessel purification:
[BALANCING TEMPLE WEALTH & CONSERVATION]
│
┌────────────────────────┴────────────────────────┐
▼ ▼
[EARTHENWARE (Cheres)] [METAL (Nechoshet)]
• Must be broken (No purging possible) • Must be scoured and rinsed
• Acceptable waste (Gezerat Hakatuv) • Avoids unnecessary destruction
• Permitted to reuse until eating period ends • Preserves valuable Temple property
- Earthenware: Because earthenware cannot be purged, it must be broken. To minimize waste, the Rambam rules in 8:14 that the priests do not need to break the vessel immediately after cooking. They may continue to reuse it for multiple offerings throughout the day, only breaking it once the permitted eating period has fully expired.[^16]
- Metal: Because metal can be purged, the Torah requires scouring and rinsing rather than destruction, preserving valuable Temple property while maintaining ritual purity.
Contemporary Applications
While the sacrificial laws are not practiced today, these principles continue to guide halachic decisions in several areas:
1. The Chemistry of Koshering
The distinction between earthenware and metal remains a cornerstone of modern kitchen koshering. The rule that earthenware cannot be koshered because it permanently retains absorption (eino yotzei mi-dafi) is applied strictly to materials like bone china, porcelain, and stoneware.
2. The Definition of a Garment for Ritual Laws
The discussion of what constitutes a "garment" (shem beged) after being torn is directly relevant to the laws of Tzitzit and Shatnez:
$$\text{Torn/Damaged Garment} \xrightarrow{\text{Does it retain "Shem Beged"?}} \text{Status of Tzitzit Obligation}$$
If a garment is damaged or altered, halachists use the guidelines from Ma'aseh HaKorbanot (such as the minimum size of a handkerchief) to determine if it still requires Tzitzit or if it has lost its status as a garment.^17
Takeaway
The laws of the Temple service show that physical actions and materials are elevated through precise boundaries. Whether washing a stained garment, purging a metal vessel, or waving an offering, the physical world is sanctified not by ignoring its properties, but by aligning them with the divine service.
[^1]: Sefer HaMitzvot, Positive Commandment 64; Sefer HaChinuch, Mitzvah 138. [^2]: See Rambam, Hilchot Ma'aseh HaKorbanot 5:7-10. [^3]: Hilchot Ma'aseh HaKorbanot 8:1, based on Leviticus 6:20. [^4]: Hilchot Ma'aseh HaKorbanot 8:3, based on Zevachim 93b. [^5]: Hilchot Ma'aseh HaKorbanot 8:11, based on Leviticus 6:21. [^6]: Hilchot Ma'aseh HaKorbanot 8:14, based on Zevachim 95b. [^7]: Hilchot Ma'aseh HaKorbanot 9:6-7, based on Leviticus 7:30. [^8]: Hilchot Ma'aseh HaKorbanot 9:14, based on Menachot 61b. [^9]: Hilchot Ma'aseh HaKorbanot 8:19, based on Zevachim 94b. [^10]: Or Sameach, Hilchot Ma'aseh HaKorbanot 8:19. [^11]: Rambam, Hilchot Ma'aseh HaKorbanot 8:11. [^12]: Shulchan Aruch, Yoreh Deah 121:1. [^13]: Rambam, Hilchot Ma'aseh HaKorbanot 8:12. [^14]: Shulchan Aruch, Yoreh Deah 121:2. [^15]: Tzofnath Paneach, Hilchot Ma'aseh HaKorbanot 8:11. [^16]: Hilchot Ma'aseh HaKorbanot 8:14. [^17]: See Shulchan Aruch, Orach Chaim 16.
derekhlearning.com