Yadayim, Chapter Four, Mishnah Seven
1) The Sadducees say: we complain against you, Pharisees, that you declare an uninterrupted flow of a liquid to be clean.
a) The Pharisees say: we complain against you, Sadducees, that you declare a stream of water which flows from a burial-ground to be clean?
2) The Sadducees say: we complain against you, Pharisees, that you say, my ox or donkey which has done injury is liable, yet my male or female slave who has done injury is not liable.
a) Now if in the case of my ox or my donkey for which I am not responsible if they do not fulfill religious duties, yet I am responsible for their damages, in the case of my male or female slave for whom I am responsible to see that they fulfill mitzvot, how much more so that I should be responsible for their damages?
3) They said to them: No, if you argue about my ox or my donkey which have no understanding, can you deduce from there anything concerning a male or female slave who do have understanding? So that if I were to anger either of them and they would go and burn another person’s stack, should I be liable to make restitution?
Section one: The Sadducees complain that the Pharisees declare that an uninterrupted flow is clean. What this means is that if one pours from a clean vessel into an unclean vessel what remains in the clean vessel is still clean (see Makhshirin 5:9). Interestingly, this very issue is mentioned in the Dead Sea Scrolls.
The Pharisees respond with a precedent showing that water connected to a source of impurity does not necessarily become impure. Water that flows out of a cemetery is pure, even though it is still attached to the source. So too with the flow from one vessel to the other, even though the water is attached to something unclean, the upper vessel is still clean.
Section two: The second argument in this mishnah compares damages or injury done by one’s animals with injury or damage done by one’s slaves. According to rabbinic law, a master is liable for damages done by his animals but not his slaves (see Bava Kamma 8:4). The Sadducees complain that this is illogical, for one is not liable to make sure that his animals perform mitzvoth, whereas one is liable to make sure that his slaves perform mitzvoth, such as brit milah (see Genesis 17:12) and eating the pesah sacrifice (Exodus 12:44).
Section three: The Pharisees respond that a master’s liability for his animals is only because animals have no intelligence/understanding. Since an animal has no intelligence, at least legally speaking, his master is usually liable for damages performed by the animal. In contrast, a slave may be owned by his/her master, but the slave has intelligence and independent will. Even if one angers his slave and the slave damages some property, the owner is not liable.
We should note that this Pharisaic law was probably unusual and perhaps even their own invention. Most law systems of the time, including other ancient near eastern laws, would have held a master liable for damages done by a slave. But for the rabbis, the operative principle in many matters of law is “legal awareness” or “understanding.” Since slaves have such capacity, they are independent and liable for damages they perform.