1. The Mishnah discusses the law of Batei Arei Chomah.
2. May the seller redeem the house immediately after he sells it?
3. The Mishnah and Beraisa disagree about the application of the prohibition of interest to the redemption of Batei Arei Chomah.
4. Rebbi Aba bar Mamal discusses the case of two Batei Arei Chomah that were sold in a leap year. One was sold on the fifteenth of Adar Rishon, and the second was sold on the first of Adar Sheni.
5. The buyers of Batei Arei Chomah used to hide from the sellers at the end of the twelve months in order to prevent them from redeeming their homes.
A BIT MORE
1. These are houses in a walled city. The law is that if someone sells such a house, he has twelve months (to the date, see #4) to redeem it from the buyer. If he does not redeem it by the end of twelve months, the buyer keeps the house.
2. Rebbi: The seller cannot redeem it within the first two days after he sells it. Rabanan: He may redeem it right away.
3. The Mishnah states that the redemption is similar to taking interest, because the buyer was able to live in the house during the year, and he receives the same amount of money back that he gave for it. The Beraisa maintains that this indeed is called interest, but the Torah permits it in this case. The Gemara presents various explanations for why it is either "similar to" (Mishnah) or "definitely" (Beraisa) the prohibition of interest.
4. The house sold on the fifteenth of Adar Rishon may be redeemed up to two weeks later than the house sold on the first of Adar Sheni. The verse states "from day to day," implying that it may be redeemed until that date of the following year.
5. Hillel therefore decreed that the redeemer may deposit his redemption money in a place in the Azarah and then break into the house (and keep it).