Bava Batra, Chapter One, Mishnah Four
Mishnah four continues to discuss a wall built in a courtyard owned by two partners, a topic that began in the first mishnah of the chapter.
1) If the wall of a courtyard fell down they obligate each of the partners to help in building it up to a height of four cubits.
a) He is presumed to have paid [his share] unless the other brings proof that he has not paid.
2) [If the fence was built] four cubits or higher, they do not obligate him [to help in building it.]
a) If [the one who did not contribute] built another wall near it, even if he did not put a roof upon it, they obligate him to share in all of the costs.
b) He is presumed not to have paid [his share] unless he brings proof that he has.
In the times of the mishnah, a standard wall, built in a courtyard was about four cubits high (over two meters, a little less than seven feet). Therefore, if the previous wall fell down, each partner would be obligated to rebuild the wall until it was four cubits high. If Reuven claims that Shimon did not pay his share, Reuven must bring proof. Since this law is commonly known, we assume that Reuven would not have begun to build the wall until Shimon paid his share. If he did build the wall without first collecting, he must bring proof that Shimon still owes him money.
In contrast, if Reuven built the wall over four cubits, he cannot ask Shimon to pay for the costs of the added height. Since walls are not commonly built over four cubits high, Shimon can claim that he did not want such a high wall. If however, Shimon were to use the wall to support another wall, and show that he intended to lay a roof on the two walls, he must pay for the added height. Although he was not initially obligated, since he subsequently used the wall, he is obligated to pay for it. Since this law is not commonly known, we cannot assume that Shimon paid his share. Until he brings a receipt showing that he has paid for the wall, he will still be obligated towards Reuven.
Questions for Further Thought:
· What is the connection between mishnah three which we learned yesterday and mishnah four? What similar idea is mentioned in both mishnayoth?