Deuteronomy 19:11-12

Thomson(i) 11 But there must not be among you one guilty of blood. If therefore there be among you a man who hateth his neighbour, and who shall lie in wait for him, and rise up against him, and smite him so that he die, and flee to one of these cities; 12 the senate of his city shall send and take him thence, and deliver him into the hands of the avenger of blood, and he shall be put to death.