פּירוש אויף שמות 21:33

“When a person opens a pit” [21:33]. When a person opens a pit or digs a pit and does not cover it and an ox falls into it, he must pay the whole damage.

וכי יפתח איש בור AND IF A MAN SHALL OPEN A PIT which was covered over, and he now uncovered it.

וכי יפתח איש בור, If a man opens the lid over a pit (which had been placed there to protect pedestrians); the Torah refers to a pit which had remain fully covered for a long time, or even if that person had a dug pit which had never been in that place, and he had not bothered to cover it because he intended to dig deeper on the following day;

או כי יכרה OR IF A MAN SHALL DIG [A PIT] — Why is this stated? If he becomes liable for opening one that already exists how much the more is he liable for digging a new one! However, it does not mean that he digs a pit from beginning to end but it is intended to include in this law a person who digs after another has dug (i. e. who deepens to a height of ten handbreaths a pit which another has already excavated to a depth less than this. Before he did this an animal which fell into the pit was unlikely to kill itself; now, however, such a fall may prove fatal) — that such a one alone becomes liable (cf. Bava Kamma 51a).