Who is Rabbi Oshaya l, an amora, and what is his relationship with tannaitic literature. The daf discusses how a seller can use produce to pay a debt.

Is interest recoverable? It's a machloket, of course. Plus, how that plays out in the Jewish vs. non-Jewish courts, and the ways they functioned differently. Also, elaborating on the mishnah's case of rising market price, and a trade for another product, which (in this specific case) turns the seller into the borrower...

Chapter 5! A new mishnah, a new topic - moneylending, and the prohibition against taking interest. Also, the sidebar explanation for addressing the exodus from Egypt in the context of interest.

The final two mishnahs of the fourth perek deal with deceptive practices shopkeepers may not do because they hurt the buyer.

The daf tells one of the most famous stories in the Gemara - Tanur Shel Akhnai. But why this story appears and the lessons to be learned from the disagreement between Rabbi Eliezer and the sages are often misunderstood. So why does this story appear in Bava Metzia and what does it teach us?

Consecrated items for which one bears responsibility are subject to price fraud, but when one is not responsible, price fraud is irrelevant. But what does it mean for the consecrated property to belong to God? What about the human dimension? Plus, taking advantage of market demands, for better and worse. Also, a new mishnah - on "ona'at devarim" -- oppression or exploitation or just plain obnoxious speech.

When is the capacity to take advantage of another not relevant? And if there's no risk of exploitation, is there any recourse to cancel the transaction for other reasons? Note the exceptions of consecrated property (hekdesh) and land... Also, what if transactions or loans are made in conjunction with consecrated property? The Temple has some flexibility with fluctuations in the costs of things - without it being exploitative.

A Mishnah lists cases where onaah does not apply and the Gemara discusses the scriptural sources for these categories.

2 mishnayot - Mishnah 1: Determining the differential to be considered exploitative, the amount to swear, and the amount to admit to owing money. Plus, 5 cases that depend on the equivalent of one perutah. Also, Mishnah 2: 5 halakhic categories for which "one-fifth" is relavant as an element of the halakhah.

The daf discusses a variety if different aspects about the chomesh.

The daf discusses what to do if one’s maaser sheini produce is worth less thana perutah and need to deconsecrate it onto coins.

A new mishnah! The erosion of minted coins, and its diminished value, with the potential for fraud in using it, as the metal is worn away. Subject to a dispute between our mishnah and a beraita. Also, the Gemara in the second part of the mishnah - garments vs. coins, and how they're handled in the village vs. cities, where the moneylenders were available to check the coins. Plus, the application of a "generosity of spirit."

A mishnah discusses if there is a time limit to claim price fraud. Also discussed if fraud can be committed by a person irrespective of a business or both? Rav and Shmuel debate if a seller can make a stipulation about price fraud in a sale.

Establishing ona'ah at pricing that is a sixth over the value - with that time frame to consult and complain as temporary recourse. When is the sale considered final? Is that time limit really necessary? Also, once there's fraud, does it matter how extreme the fraud is? (Yes) Or how long the deadline really is? A close reading of the mishnah helps explain the overcharge.

Reneging on a verbal commitment toward a sale - illustrative stories. Also, a new mishnah! On "ona'ah" - cases of taking advantage of another in a measurable way that is already determined to be problematic. Plus, terms whereby a customer can walk back terms that smack of ona'ah.

The daf explores the idea of Mi Sh’Para and what happens of someone reneges on a sale and the beit din cannot enforce the sale.

Defining "kinyan sudar" - a handkerchief version of halipin. Plus, "kinyan agav," where the act of acquisition is secondary and along the way of the acquisition of something else, usually movable items along with a purchase of land. Also, using exchange when you have no money or anything else of value to use for purchase.

More on exchange - including the question of using a coin as an indication of a formal act of acquisition. For it to work, he has to already have the coins in hand. Otherwise, it's too close to a sale. Also, Rav Nachman's opinion, the idea that money does effect the purchase by Torah law, and the exchange of money bags.

One who redeems ma'aser sheni on coins, and the desacralizes the coins to use them to buy the food in Jerusalem - how those coins can be exchanged, a dispute between Beit Shammai vs. Beit Hillel. Plus, the sourcing of the word "money" twice in the biblical verse. Also, when money is an exchange instead of a sale or a purchase payment.

The third perek finished with a discussion about whether intent to misappropriate a deposit is misappropriation. The fourth perek begins with a mishnah discussing how objects are acquired.

2 mishnayot! Additional cases of an object left with a guardian, and how various variables change the guardian's liability. Note the differences between a store keeper, a money changer, and a guardian. Plus, the complications of a change in value and the obligation to replace an unprotected item. Also, when one has to pay the increased value, for wine, for example. Plus, Rabbi Akiva's opinion upheld.

A new mishnah! When a guardian doesn't take good care to protect coins... when is he liable? With a focus on the verses that insist on proper supervision. Also, the blessing that only appears in that which is not obviously visible. Plus, storing money in a place that is protected from one potential threat, but subject to another one. Likewise, the question of whether negligence is relevant when a guardian puts the thing he's protecting under the protection of another. With a slew of cases to...

The daf discusses the last mishnah on 40 about whether a barrel being watched may be moved. A disagreement is presented between Rav and Levi if an act is considered misappropriation only if there is actual depletion of the object’s value

Two mishnahs detail how a shomer may deduct from the quantity of produce or liquids left with the shomer when it is returned to the owner.