Numbers 35:19

35:19 The avenger of blood himself must kill the murderer; when he meets him, he must kill him.

Numbers 35:21

35:21 or with enmity he strikes him with his hand and he dies, the one who struck him must surely be put to death, for he is a murderer. The avenger of blood must kill the murderer when he meets him.

Numbers 35:27

35:27 and the avenger of blood finds him outside the borders of the town of refuge, and the avenger of blood kills the slayer, he will not be guilty of blood,