These are the ones who are exiled: One who kills a person inadvertently. [If] he was pushing out with a roller, and it fell upon him and killed him; [or if] he was letting down a cask, and it fell upon him and killed him; [or if] he was descending a ladder, and he fell upon him and killed him —- he is exiled. But if he was drawing back the roller, and it fell upon him and killed him; [or if] he was hoisting up the cask and the rope broke, and it fell upon him and killed him; [or if] he was ascending the ladder, and he fell upon him and killed him —- he is not exiled. This is the rule: For [any death which occurs] in the course of descent, he is exiled; but for [one which occurs] not in the course of descent, he is not exiled.  Should the iron fly off its handle and kill —- Rabbi says: He is not exiled; but the Sages say: He is exiled. From the tree that is being chopped —- Rabbi says: He is exiled; but the Sages say: He is not exiled.

[If] one throws a stone into a public domain and kills, he is exiled. R' Eliezer ben Yaakov says: If, after the stone left his hand, the other one put his head out and received the blow, he is exempt. [If] he threw a stone into his own yard and killed —- if the victim had a right to enter there, he is exiled, but if not, he is not exiled; as it is said (Deut. 19:5): And whoever comes with his fellowman into the forest —- [it must be] like the forest, which is a place into which [both] the victim and the assailant have permission to enter. This excludes the courtyard of the householder, into which the victim and the assailant may not [both] enter. Abba Shaul says: [It must be] like chopping wood, [which is] an optional act. This excludes the father who hits his son, and the teacher who chastises his pupil, and the agent of the court.