Tractate Yadayim - Chapter 4 - Mishnah 7 ידיים פרק ד׳ משנה ז׳

The Sadducees say: we complain against you, Pharisees, that you declare an uninterrupted flow of a liquid to be clean. The Pharisees say: we complain against you, Sadducees, that you declare a stream of water which flows from a burial-ground to be clean? 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. 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? 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?