Numbers 35:21-23

Amplified Bible

²¹ or if, in enmity, he struck the victim down with his hand, and he died, the one that struck the victim shall certainly be put to death; he is a murderer. The blood avenger shall put the murderer to death when he meets him.

²² ‘But if he pushed the victim suddenly, not in enmity, or threw anything at him without malicious intent, ²³ or without seeing him hit him [accidentally] with a stone object that could kill him, and he died, and [the offender] was not his enemy nor intending to harm him,