Numbers 35:19 in the King James Version
The revenger of blood himself shall slay the murderer: when he meeteth him, he shall slay him.
Context
18 Or if he struck him with a weapon of wood in the hand, by which a man may die, and he died, he is a murderer. The murderer shall surely be put to death.
19 The avenger of blood shall himself put the murderer to death. When he meets him, he shall put him to death.
20 If he shoved him out of hatred, or hurled something at him while lying in wait, so that he died,