Numbers 35:12
"And they shall be unto you cities for refuge from the avenger; that the manslayer die not, until he stand before the congregation in judgment."
Cross References (ranked by relevance)
Lest the avenger of the blood pursue the slayer, while his heart is hot, and overtake him, because the way is long, and slay him; whereas he was not worthy of death, inasmuch as he hated him not in time past.
And, behold, the whole family is risen against thine handmaid, and they said, Deliver him that smote his brother, that we may kill him, for the life of his brother whom he slew; and we will destroy the heir also: and so they shall quench my coal which is left, and shall not leave to my husband neither name nor remainder upon the earth.
These were the cities appointed for all the children of Israel, and for the stranger that sojourneth among them, that whosoever killeth any person at unawares might flee thither, and not die by the hand of the avenger of blood, until he stood before the congregation.
The revenger of blood himself shall slay the murderer: when he meeteth him, he shall slay him.