Mishnah — Seder Nezikin, Tractate Bava KammaChapter 1…
“ Nor are any of these, which are wont to move and do damage, similar to the pit, which is not wont to move and do damage. The common denominator among them is that they are inclined to do damage, and the duty of their care is upon you, and if they do damage, the defendant must pay from the best land. ”
