Joshua

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.

The revenger of blood himself shall slay the murderer: when he meeteth him, he shall slay him.

But if he thrust him suddenly without enmity, or have cast upon him any thing without laying of wait,

And the congregation shall deliver the slayer out of the hand of the revenger of blood, and the congregation shall restore him to the city of his refuge, whither he was fled: and he shall abide in it unto the death of the high priest, which was anointed with the holy oil.

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.