Shmuel 2:1

Now this is the case of the רוצח who may flee there and live: one who has killed another unwittingly, without having been their enemy in the past. For instance, a person goes with their neighbor into a grove to cut wood; as their hand swings the ax to cut down a tree, the ax-head flies off the handle and strikes the other so that they die. That person shall flee to one of these cities and live.

The following are exiled: one who kills a person accidentally. If one was pushing a roller [on a roof] and it fell on them [a bystander] and killed them, or if one was lowering a barrel [from a roof] and it fell and killed them [a bystander], or if one was descending a ladder and fell and killed them [a bystander], all of these cases they [the killer] are exiled. However, if one was pulling a roller and it fell and killed the person, or if one was raising a barrel and the rope tore and it fell and killed a person, or if one was climbing a ladder and fell and killed a person, in these cases they [the killer] would not be exiled. This is the principle: If the killer was involved in a downward movement, they are exiled. If it is not a downward movement they are not exiled. If the blade came off the handle and killed, Rebbi says one is not exiled but the Sages say they are exiled. If it came from the wood being chopped, Rebbi says one is exiled but the Sages say they are not exiled.

(2) One who throws a rock into the public domain and it kills someone is exiled. Rabbi Eliezer ben Yaakov says: if the person stuck their head into the public domain only after the stone left their [the killer's] hand, one is exempt. If they threw the stone into his courtyard and it killed, if the victim had permission to be there, they are exiled, but if they did not have permission, they are not exiled, as it says, "If one comes upon their fellow in the woods..." (Deuteronomy 19:5). Just as the woods is open to both the victim and the perpetrator to enter there, this excludes a privately owned courtyard where both the victim (and the perpetrator) do not have permission to be there. Aba Shaul says: Just as chopping wood is optional, [so too one is only exiled for optional activities]. This excludes a father beating his son, a teacher disciplining their student, and the messenger of the courts.