Deuteronomy 19:12

“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.

“If, however, a man acts presumptuously toward his neighbor, so as to kill him by deceit, you shall take him even from My altar, that he may die.

then you shall select for yourselves cities to be your cities of refuge, that the manslayer who has struck down any person unintentionally may flee there.

Then Moses set apart three cities across the Jordan to the east toward the sunrise,

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

“For he took his life in his hand and struck the Philistine, and Yahweh brought about a great salvation for all Israel; you saw it and were glad. Why then will you sin against innocent blood by putting David to death without a cause?”

“And behold, the whole family has risen against your servant-woman, and they say, ‘Hand over the one who struck his brother, that we may put him to death for the life of his brother whom he killed, and destroy the heir also.’ Thus they will extinguish my coal which remains, so as to leave my husband neither name nor remnant on the face of the earth.”