Homicide. Exodus 21:12 reiterates the Sixth Commandment, and adds to it a temporal penalty—"he shall surely be put to death." The substance of this law had already been given to Noah in the words, "Whoso sheddeth man' s blood, by man shall his blood be shed" (Genesis 9:6).
Real murder, with deliberate intent, was under no circumstances to be pardoned. The murderer was even to be torn from the altar, if he took refuge there, and relentlessly punished (Exodus 21:14). See the case of Joab (1 Kings 2:28-34).
But, if a man happened suddenly upon his enemy, without having sought the opportunity, and slew him (Exodus 21:13), then the case was one not of murder, but at most of manslaughter, or possibly of justifiable homicide.
No legal penalty was assigned to such offences. They were left to the rude justice of established custom, which required "the avenger of blood" to visit them with due retribution. According to the general practice of the Eastern nations, he might either insist on life for life or take a money compensation.
With this custom, deeply ingrained into the minds of the Oriental people, the law did not meddle. It was content to interpose between the avenger of blood and his victim the chance of reaching an asylum.
Places were appointed, whither the shedder of blood might flee, and where he might be safe until his cause was tried before the men of his own city (Numbers 35:22-25), and afterwards, if the judgment were in his favour.
Some particular part of the camp was probably made an asylum in the wilderness.