Beraisa #1: If Reuven asked a moneychanger (Levi) about a certain coin, and Levi said that it is good, and it turned out to be bad, if he is an expert moneychanger, he is exempt. If not, he is liable;

Contradiction (Beraisa #2): In either case, he is liable.

Answer (Rav Papa): Beraisa #1 exempts a very proficient moneychanger, who has learned everything he needs to know.

Question: If so, how did he err?

Answer: They had just changed the coinage, and he did not yet hear about this.

A woman showed a coin to R. Chiya. He told her that it is good. It turned out to be bad. He gave her a good coin in its place, and recorded his loss like a 'bad deal'.

Question: R. Chiya had learned everything that he needed to know!

Answer: He acted beyond the letter of the law.

(Rav Yosef): "You will make them know" refers to Talmud Torah. "The way" refers to bestowing Chesed. "They will go" refers to visiting the sick. "In it" refers to burial. "The deed" refers to the law. "That they will do" refers to going beyond the letter of the law.

Reish Lakish showed a coin to R. Elazar. He told him that it is good.

Reish Lakish: You should know that I rely on you.

R. Elazar: Do you expect me to pay if I am wrong? You yourself say that R. Meir is the Tana who obligates for Garmi!

Suggestion: This means that R. Meir obligates, but the Halachah does not follow him!

Reish Lakish: No, the Halachah follows R. Meir.

Question: Where do we find that R. Meir obligates for Garmi?

Answer #1 (Mishnah): If a judge acquitted the guilty party, obligated the exempt party, declared Tamei what is really Tahor, or declared Tahor what is really Tamei, what he did is done, and the judge must pay (for any resulting loss. A Stam Mishnah is assumed to be R. Meir.)

Rejection: R. Ila'a said that the Mishnah discusses a judge who acted on his ruling (e.g. he transferred the money himself, touched Tum'ah to the food (to 'prove' that it is Tamei), or mixed the 'Tahor' food with Taharos) which is standard damage, not Garmi).

Answer #2 (Mishnah - R. Meir): If Reuven gave wool to Shimon to dye red, and he died it black, or vice-versa, Shimon pays him the value of the wool he received.

Rejection: There, he damaged through his action (that is not Garmi).

Answer #3 (Mishnah): If Reuven draped his vines over Shimon's grain, this forbids the grain, and Reuven is liable.

Rejection: There also, he damaged through his action.

Answer #4 (Beraisa): If the wall between Reuven's vineyard and Shimon's grain field was breached, and Shimon told him to fix it; it was breached, and he told him to fix it;

If Reuven decided not to fix it, this forbids the grain, and Reuven is liable.

(Mishnah): If Reuven gave wool to a dyer (Shimon), and the dye was ruined, Shimon pays the value of the wool.

If he dyed it poorly, Reuven pays the increased value of the wool or Shimon's expenses, whichever is smaller.

R. Meir says, if he was told to dye it red, and he died it black, or vice-versa, Shimon pays the value of the wool he received;

R. Yehudah says, Reuven pays the increased value or Shimon's expenses, whichever is smaller.

(Gemara) Question: What does 'he dyed it poorly' mean?

Answer (Rav Nachman): He dyed it with Kalbus.

Question: What is this?

Answer (Rabah bar Shmuel): It is the dregs of dye at the bottom of the cauldron.