The Bible
Numbers 35
The Levites are to possess their own cities—Cities of refuge are established for those guilty of manslaughter—Murderers are to be executed by the revenger of blood.
1And the Lord spake unto Moses in the plains of Moab by Jordan near Jericho, saying,
9¶ And the Lord spake unto Moses, saying,
13And of these cities which ye shall give six cities shall ye have for refuge.
19The revenger of blood himself shall slay the murderer: when he meeteth him, he shall slay him.
20But if he thrust him of hatred, or hurl at him by laying of wait, that he die;