Bava Kamma 050

1:
We recall that the very first mishnah of this tractate, which serves as a kind of general introduction, stated that the Torah posits four major sources of possible damage: "the ox, the pit, the grazer and the incendiary". The possible damage caused by an ox (and other animals) was dealt with quite extensively in the first chapters of the tractate; damage caused by a pit was the subject of the closing mishnahs of chapter 5. So it is quite natural that chapter 6 now opens the discussion concerning the third category of damages, 'the grazer'.

2:
The 'grazer' is, of course, a term which denotes damage caused to property by animals grazing where they shouldn't. The main offenders are the flock animals – sheep and goats. It was customary in mishnaic times for householders to keep their sheep and their goats very near to their living space – in a garden or in the courtyard.

3:
Our present mishnah teaches that one who owns flock animals (probably, one or two of each kind) must ensure that they are properly locked in: if they can roam free they will cause great damage to the property of others. The sheep will graze freely on any grasses that come their way and the goats will try to eat almost anything that looks as if it may be food. As we shall see at the end of chapter 7, in the end the sages had to prohibit the possession by individuals in Eretz-Israel of flock animals not only because of the damage they inflicted on private property but because they were also denuding every local copse of its greenery.

4:
The Gemara [BK 55b] discusses what might reasonably be considered adequate precautions to prevent sheep and goats from wandering through the village and the countryside. We naturally think of pens with fences and lockable gates. But when we recall that the animals were usually kept very close to the family's living quarters we can understand the decision of the Gemara:

In other words, the flock owner must ensure that his animals are enclosed in such a way that they cannot escape. He is not required to hire guards for the night or, in modern terms, to install electric surveillance; but he must ensure that the gate of the pen is such that it could remain standing in a normal breeze.

5:
We could perhaps wonder why the sages are so lenient in this matter. After all, they could have demanded much more efficient means of enclosing the flock animals, particularly since they were capable of doing so much damage. Their reasoning will become apparent if we first consider the biblical verse [Exodus 22:4] which is the basis for all considerations concerning flock animals:

The sages note carefully the wording of the Torah: it is the owner who 'sets loose' his livestock who is culpable: he has deliberately let his animals loose to graze onto someone else's land. It follows that if the animals escaped without the connivance of their owner it would be a different situation. Therefore the sages hold that it is sufficient for the owner to take reasonable precautions to prevent his animals from escaping, but no more.

6:
Our mishnah adds a clause concerning a break in the fence at night. Why at night? The sages hold that the owner cannot be faulted for the escape of his animals if the fence of their pen is broken open at night: how is he to know? But if the fence is broken during the day he would be liable: he can see the damage and must repair it.

7:
In his commentary on our mishnah Rambam explains the clause concerning robbers:

If the robbers break in for some purpose other than stealing the sheep and through their negligence the sheep escape they may not be guilty of theft, though they would be held liable for damages caused by the animals. But if the robbers take pains to get the animals out of the pen, even if they don't actually touch them, they are guilty of theft as well as liable for damages.

Juan-Carlos Kiel writes:

In thelast shiur you quote Leviticus 19:19: "You shall not let your cattle mate with a different kind" and have Rashi extend it to "The same rule applies to any two species". However, mules (a hybrid between a donkey and a mare) were bred since early antiquity. Were mules forbidden for Jews?

I respond:

No, mules were not forbidden. The Torah does not legislate against a donkey mounting a mare or a horse mounting a she-ass. The Torah legislates against human beings causing such a combination. For the sake of completeness I bring here Rambam's resume of the law in his Mishneh Torah [Kilayim 9:6]:

The things one learns when studying Mishnah!