Numbers 35:12

“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.

“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,

‘Now if the avenger of blood pursues him, then they shall not surrender the manslayer into his hand because he struck his neighbor without premeditation and did not hate him beforehand.

‘And he shall live in that city until he stands before the congregation for judgment, until the death of the one who is high priest in those days. Then the manslayer shall return and come to his own city and to his own house, to the city from which he fled.’”