Chullin 110 - How Much Milk To Cook a Pound of Meat?
Rav once heard a certain housewife ask her friend, "How much milk is required to cook a pound of meat?" On hearing this, Rav enacted in Sura a law prohibiting eating the udder altogether. He also established there an academy that lasted for 800 years.
Rami bar Tamrei visited Sura on the eve of Yom Kippur. The people, preparing a pre-Yom Kippur meal, threw the udders into the street, and he collected and ate them. They brought him to Rav Chisda, where the following dialog ensued.
Ch: Why did you eat the udders in violation of the local custom?
R: I am from a place of Rav Yehudah, who allows to eat udders.
Ch: But don't you agree to the rule that if you are in a place of a more stringent custom, you don't violate it?
R: I ate them outside the city limit.
Ch: And with what did you roast the udders?
R: With grape pits that I found near a winepress.
Ch: But perhaps they were from wine use for libations?
R: They were older than 12 months and thus permitted for benefit.
Ch: But perhaps they were stolen goods?
R: The owners abandoned them, there were nettles sprouting there.
Rav Chisda saw that Rami was not wearing tefilin.
Ch: Why are you not wearing tefilin?
R: He (that is, I) suffers from stomach ailment.
Ch: And why are not wearing tsitzit fringes?
R: My garment is borrowed.
Meanwhile, they brought a person to be punished with lashes, because he refused to honor his parents. Rami said, "Release him!" There is no punishment for a commandment if a reward for it is mentioned next to it in the Torah.
Rav Chisda relented and said, "I see that you are very sharp." Rami replied, "If you would be in Rav Yehudah's city, I would show you my sharpness!"
Art: Lorenzo Lotto - Portrait Of A Young Scholar