The revenger of blood - גאל הדם goel haddam, the redeemer of blood; the next in blood to him who was slain. See on Num 35:12 (note).

The revenger of blood himself shall slay the murderer,.... Not only shall have power to do it, but, as it seems, should be obliged to do it; be the executioner of the murderer; but not before his case has been heard, examined, tried, and judged; wherefore the Targum of Jonathan adds,"in judgment,''that is, as Onkelos explains it,"when he is condemned by judgment,''the court of judicature:

when he meeteth him he shall slay him; the first opportunity he has, even though, as Jarchi says, if he meets him in the midst of one of the cities of refuge, and no judgment is passed on him.

If he smite him with an instrument of iron, so that he die, &c.--Various cases are here enumerated in which the Goel or avenger was at liberty to take the life of the murderer; and every one of them proves a premeditated purpose.