Numbers 35:21-23

New English Translation

²¹ or with enmity he strikes him with his hand and he dies, the one who struck him must surely be put to death, for he is a murderer. The avenger of blood must kill the murderer when he meets him.

²² “But if he strikes him suddenly, without enmity, or throws anything at him unintentionally, ²³ or with any stone large enough that a man could die, without seeing him, and throws it at him, and he dies, even though he was not his enemy nor sought his harm,