Question: It is understandable that one may not lend them items (within 3 days of their festival), but why may one not borrow?

Answer: Because the idolater will feel important that a Jew needs him and will go and thank his idol for this.

Question: It is understandable that one may not lend them money (within 3 days of their festival), but why may one not borrow money?

Answer: Because the idolater will feel important that a Jew needs to borrow money from him and will go and thank his idol for this.

Question: It is understandable that one may not pay back a debt to them, but why may one not collect a debt from them?

Answer: As he will thank his idol for helping him to pay off his debt.

(R. Aba bar Tavlai citing Rav): If there is a possibility that unless he collects it now, he will not be able to collect it later, he may collect it.

Proof (Beraisa): One may collect a debt that might be lost - this refers to a 'verbal' loan that was borrowed only with witnesses but without a document. Since the borrower could deny having borrowed it, it is called a debt that might be lost. But there is no concern that a loan borrowed with a document will be lost, as the borrower cannot merely deny it.

Rebuttal: Even a loan with a document might be lost - as sometimes the idolater might avoid repaying it completely; therefore, even such a loan may be collected on the day of their festival.

Question: If so, when did the Mishnah say that one may not collect a debt?

Answer: A loan without collateral might be lost; a loan with collateral will not be lost. (The latter is the case of the Mishnah.)

There is a Beraisa that teaches as we originally learned - a loan with only witnesses (but no document) is a loan that might be lost; but a loan with a document is not lost.

Mishnah in Moed Katan (R. Yehuda): A woman may not plaster her face (for hair removal) on Chol Hamoed, as it pains her as long as it is still on her skin.

There was dispute between R. Chanina and R. Mana - one said that the Tannaim disagree when she will remove the plaster during the Moed; but all agree that if she will only remove the plaster after the Moed, it is prohibited.

The other opinion reasons - they disagree over when she will remove the plaster after the Moed, but if she will remove it during the Moed, all agree that it is permitted.

They did not know who held which opinion. However, from the statement of R. Chanina/ R. Yosi citing R. Yochanan that when R. Yehuda said that one may collect a debt from an idolater before their festival, he follows his reasoning, that a woman may not plaster her face on Chol HaMoed...just as R. Yehuda said there that there is temporary pain for her during the Moed if she does this, which is prohibited, even though she will be happy later on; so too, one may collect a debt from an idolater before his festival, as even though he will be happy later on, he is pained at the time of repayment.

Let us say that it is R. Chanina that said they disagree over plaster that will be removed during the Moed, but if it will be removed after the Moed, all agree that it is prohibited.