MISHNA: In the case of one who pours water in the public domain, and another person incurred damage due to it, the one who poured water is liable to pay for his damage. In the case of one who conceals a thorn or a piece of glass in his wall adjacent to the public domain, or one who puts up a fence of thorns, or one who puts up a fence that subsequently fell into the public domain, and others incurred damage due to any of these, he is liable to pay for their damage.
The Sages taught (Tosefta 2:6): With regard to one who conceals his thorns or his pieces of glass in another’s wall, and the owner of the wall came and demolished his wall and it fell into the public domain, and the thorns or glass caused damage, the one who concealed them is liable. Rabbi Yoḥanan says: They taught this only in the case of an unstable wall, since the one who concealed his items should have anticipated that the owner of the wall would soon demolish it, but in the case of a stable wall, the one who concealed his items is exempt, and the owner of the wall is liable.
Ravina says: That is to say that in the case of one who covers his pit with another’s bucket, and the owner of the bucket came and took his bucket, and the pit causes damage, the owner of the pit is liable.
The Gemara asks: Isn’t this obvious? What is the novel element in Ravina’s statement?
The Gemara answers: It is necessary. Lest you say: It is only there, in the case of the thorns, that the owner of the wall is exempt, since he did not know who concealed the hazardous item in order to inform him that he should remove them, but here, since the owner of the bucket knew who dug the pit, he should have informed him that he was taking his bucket and is consequently liable to pay for damage caused by the pit, Ravina therefore, teaches us that he is not required to inform the owner of the pit, and he bears no responsibility for any damage caused.
The Sages taught: The early pious people would conceal their thorns and their pieces of glass in their fields, and would dig to the depth of at least three handbreadths in order to bury them, so that they would not obstruct the plow.
The Gemara relates: Rav Sheshet would toss his thorns into fire, so they would not cause damage to others. Rava would toss them into the Tigris [Diglat] River.
Rav Yehuda says: One who wants to be pious should observe the matters of tractate Nezikin, so as to avoid causing damage to others. Rava said he should observe the matters of tractate Avot. And some say he should observe the matters of tractate Berakhot.
§ The Sages taught: A person should not throw stones from his property into the public domain. An incident occurred involving a certain individual who was throwing stones from his property into the public domain, and a certain pious man found him. The latter said to him: Lowlife [reika], for what reason are you throwing stones from property that is not yours into your property? The man mocked him, as he did not understand what he meant, as the property from which he was throwing stones was his.
Some days later, he was forced to sell his field from which he had thrown the stones. And he was walking in the same public domain into which he had thrown them, and he stumbled on those same stones. He said: That pious man said it well to me when he said: For what reason are you throwing stones from property that is not yours into your own property, since that property no longer belongs to me, and only the public domain remains mine to use.