Numbers 35:31

“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.

‘If a man strikes down the life of any human being, he shall surely be put to death.

‘And if he struck him down with a stone in the hand, by which he would die, and as a result he died, he is a murderer; the murderer shall surely be put to death.

“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—

‘Cursed is he who strikes his neighbor in secret.’ And all the people shall say, ‘Amen.’

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

These were the appointed cities for all the sons of Israel and for the sojourner who sojourns among them, that whoever strikes down any person unintentionally may flee there and not die by the hand of the avenger of blood until he stands before the congregation.

Then the Gibeonites said to him, “We have no concern of silver or gold with Saul or his house, nor is it for us to put any man to death in Israel.” And he said, “I will do for you whatever you say.”