Numbers 35:11

“But if he did not lie in wait for him, but God let him fall into his hand, then I will appoint you a place to which he may flee.

‘These six cities shall be for refuge for the sons of Israel and for the sojourner and for the foreign resident among them; that anyone who strikes a person down unintentionally may flee there.

‘But if he pushed him suddenly without enmity or threw something at him without lying in wait,

“Now this is the case of the manslayer who may flee there and live: when he strikes down his friend without premeditation, not hating him previously—

“Speak to the sons of Israel, saying, ‘Designate the cities of refuge, of which I spoke to you by the hand of Moses,