Bava Batra

[One] Ronya had a field which was enclosed on all four sides by fields of Rabina. The latter [fenced them and] said to him: pay me [towards] what I have spent for fencing.  He refused to do so. Then pay [towards] the cost of a cheap fence of sticks.  He again refused. Then pay me the hire of a watchman.  He still refused. One day Rabina saw Ronya gathering dates, and he said to his metayer: Go and snatch a cluster of dates from him. He went to take them, but Ronya shouted at him, whereupon Rabina said: You show by this  that you are glad of the fence. If it is only goats [you are afraid of], does not your field need guarding? He replied: A goat can be driven off with a shout.  But, he said, don't you require a man to shout at it? He appealed to Raba, who said to him: Go and accept his last offer,  and if not, I will give judgment against you according to R. Huna's interpretation of the ruling of R. Jose. Ronya bought a field adjoining a field of Rabina. The latter thought he was entitled to eject him in virtue of his right of preemption.  Said R. Safra the son of R. Yeba to Rabina: You know the saying, The hide costs four zuzim, and four are for the tanner. MISHNAH. IF THE PARTY WALL OF A COURTYARD FALLS IN, EACH OF THE NEIGHBOURS CAN BE COMPELLED BY THE OTHER TO [CONTRIBUTE TO THE COST OF] REBUILDING IT TO A HEIGHT OF FOUR CUBITS.  [EACH OF THEM] IS ALWAYS PRESUMED TO HAVE GIVEN HIS SHARE  UNTIL THE OTHER BRINGS A PROOF THAT HE HAS NOT GIVEN.  FOR REBUILDING HIGHER THAN FOUR CUBITS NEITHER CAN BE COMPELLED [TO CONTRIBUTE]. IF, HOWEVER, [THE ONE WHO HAS NOT CONTRIBUTED]  BUILDS ANOTHER WALL CLOSE TO IT,  EVEN THOUGH HE HAS NOT YET PUT A ROOFING OVER THE SPACE BETWEEN, THE [PRO RATA] COST OF THE WHOLE DEVOLVES UPON HIM,  AND HE IS PRESUMED NOT TO HAVE GIVEN UNTIL HE ADDUCES PROOF THAT HE HAS GIVEN. GEMARA. Resh Lakish has laid down: If a lender stipulates a date for the repayment of a loan, and the borrower pleads [when the date of payment arrives] that he paid the debt before it fell due, his word is not accepted. Let him only pay when it does fall due! Abaye and Raba, however, both concur in saying that it is not unusual for a man to pay a debt before it falls due; sometimes he happens to have money, and he says to himself, I will go and pay him,