Daily Rambam (3 Chapters) · Beginner – Jewish Basics · On-Ramp

Mishneh Torah, Sales 13-15

On-RampBeginner – Jewish BasicsNovember 22, 2025

Here's a friendly lesson for absolute beginners on the topic of ona'ah (unfair gain) in Jewish law!

Hook

Ever bought something and later felt like you paid way too much? Or maybe you sold something and realized you could have gotten a lot more? It's a super common feeling, right? We want to be fair in our dealings, but sometimes it’s hard to know if we’re getting a good deal or if we're accidentally overcharging someone. This ancient Jewish text, the Mishneh Torah, actually dives deep into this exact issue, offering some really practical wisdom that’s still relevant today. It’s all about making sure our transactions are honest and that everyone involved feels treated justly.

Context

This text comes from the Mishneh Torah, a monumental work by the brilliant Rabbi Moshe ben Maimon, also known as Maimonides or Rambam. He lived in the 12th century and wrote this code of Jewish law to be clear and comprehensive.

  • Who wrote it? Rabbi Moshe ben Maimon (Maimonides), a towering figure in Jewish thought and law.
  • When was it written? The 12th century CE.
  • Where does it fit? It’s part of the Mishneh Torah, a systematic compilation of Jewish law covering all areas of Jewish life. This specific section is in the laws of Sales.
  • Key Term: Ona'ah (אוֹנָאָה) - This means unfair gain or exploitation in a transaction. It's about taking advantage of someone's lack of knowledge or desperation to make an excessive profit.

Text Snapshot

Here’s a little peek into what the Mishneh Torah says about ona'ah:

"When a person exchanges one article for another, or one animal for another, the laws of ona'ah do not apply... When, however, a person exchanges produce for produce, the laws of ona'ah do apply... when a person purchases an article with coins without measuring their number, volume or weight... this is considered an exchange. The transaction is completed, and the unfair gain must be returned... If, however, one explicitly mentions the amount of unfair gain, the laws of ona'ah do not apply, because all conditions that are accepted by both parties are binding in cases of financial law." (Mishneh Torah, Sales 13:1, 13:2, 13:5, 13:6)

Close Reading

Let's break down some of these ideas so they're super clear and useful!

### When is Ona'ah Not a Problem?

The text starts by saying that if you swap one thing for another, like a needle for a necklace, or a lamb for a donkey, the rules of ona'ah (unfair gain) don't usually apply. Why? Because maybe you really wanted that needle more than the necklace, or the other person really needed that donkey! This is called an exchange, and it’s different from buying and selling with money. It's like saying, "I value this more than that right now." However, when you trade one type of food for another, like apples for oranges, the rules do apply. This is because food is generally valued similarly, and it’s easier to spot if someone is being unfair.

### What About Money and Goods?

The text then gets into the nitty-gritty of buying with money. If you just grab a handful of coins and say, "Here, take this for your cow," without counting them, measuring them, or weighing them, it's treated like an exchange. The deal is done, but if there was unfair gain, it needs to be fixed. The same goes for buying fruit without measuring it. This tells us that even in informal-sounding deals, fairness is key. The law wants to make sure that when we use money to get goods, the value is reasonably balanced.

### Honesty is the Best Policy (Even If You're Upfront!)

Here's a super interesting part: the text says that you can't get around the laws of ona'ah by just saying, "Let's pretend this unfairness isn't happening." If someone says, "I'm selling you this for $200, even though it's only worth $100, but don't hold me responsible for the unfair gain," the law says that's still ona'ah! The reason is that the other person might not fully grasp how much they're losing.

BUT, and this is a big but, if you are really specific about the amount of unfair gain, then it can be allowed. For example, if the seller says, "I know this is worth $100, but I'm selling it to you for $200, and I'm telling you upfront that this $100 difference is the unfair profit I'm making," and the buyer agrees to that specific amount, then it's okay. This is because all conditions accepted by both parties are generally binding in financial matters. So, it's not about hiding the unfairness, but about being transparent about the exact amount being waived. It’s like saying, "I know this is a bit much, but I'm choosing to pay it."

### What About Selling Your Own Stuff?

When you sell your own personal belongings, the rules of ona'ah don't apply. Why? Because the text suggests that a person wouldn't sell their personal treasures unless they were offered an exorbitant amount. This implies that if you are selling your personal items, you're likely getting a price you're happy with, and the usual protections against unfair gain are less critical because you're in control.

### Faithfulness in Business

The text emphasizes doing business in a "faithful manner." This means being honest and straightforward. For example, if a seller says, "I bought this for X amount, and I'm selling it to you for Y amount, making this much profit," that’s considered faithful. It’s about transparency in your dealings.

### Special Cases: Gentles and Certain Properties

Interestingly, the laws of ona'ah don't apply to transactions with non-Jews. This is based on the verse in Leviticus that says, "one man should not cheat his brother." The implication is that this law is specifically about fairness within the Jewish community. However, if a non-Jew takes unfair advantage of a Jew, the Jew is still required to return the unfair gain according to Jewish law – meaning the standards for fairness are still high!

There are also certain types of property where ona'ah doesn't apply: land, servants, promissory notes, and consecrated property. The reasoning is often tied to the idea of ownership transfer and the specific nature of these items. For example, with land, it’s not something you can easily "hand over" in the same way as a movable object.

### What About Courts and Orphans?

When a court sells property belonging to orphans, there are specific rules. If they err by less than one-sixth of the value, it’s considered like a waiver, similar to how an individual might waive a small amount. But if the error is one-sixth or more, the sale can be nullified. The principle is that the court's power shouldn't be less than that of an ordinary person when it comes to protecting orphans' assets.

### Verbal Abuse is Also Ona'ah!

This is a really powerful point. The text extends the concept of ona'ah beyond just financial dealings to include verbal abuse. Leviticus 25:17 says, "A person should not abuse his colleague, and you shall fear your God." This isn't just about money; it's about how we speak to each other. Examples include reminding someone of their past mistakes, bringing up their lineage (especially if they're a convert), or mocking someone's suffering. The text emphasizes that verbal abuse is even worse than financial exploitation because it can never be repaid, and it affects a person's very being, not just their possessions. It highlights the deep connection between our actions and our spiritual awareness – "and you shall fear your God."

Apply It

This week, let's try a tiny practice to bring more mindfulness into our daily interactions.

### The "Pause and Consider" Practice

For the next seven days, before you respond to someone in a potentially sensitive situation (whether it's a quick text, an email, or a face-to-face chat), try this:

  1. Pause for 3 seconds. Just breathe.
  2. Consider their perspective (even if you don't agree). What might they be feeling or thinking?
  3. Ask yourself: "Is my response fair and kind?"

That’s it! It’s not about changing the world, but about bringing a little more intentionality and kindness into how you communicate. Do this once a day, whenever a moment feels right.

Chevruta Mini

Grab a friend, family member, or even just talk to yourself in the mirror (hey, we're all friends here!) and ponder these questions:

### Discussion Question 1

The text talks about how verbal abuse is worse than financial exploitation because it can't be repaid. Can you think of a time when harsh words really stuck with you, even more than a bad deal? What does that tell us about the importance of our speech?

### Discussion Question 2

The Mishneh Torah says that when you exchange one item for another (not involving money), ona'ah doesn't apply because you might value one item more than the other at that moment. Does this idea of subjective value make sense in our lives? When might you be willing to "overpay" for something because of its personal meaning to you?

Takeaway

Remember this: True fairness in Jewish tradition extends beyond just our wallets to encompass the respect and kindness we show through our words.