'Man slayer' in the Bible

[Among] the cities which you give to the Levites shall be the six cities of refuge, which you shall provide for the one who commits manslaughter to flee to; and in addition to them you shall give forty-two cities [to the Levites].

The cities shall be to you as a refuge from the avenger, so that the one who has caused the death of another will not be killed until he has had a [fair] trial before the congregation.

The congregation shall rescue the offender from the hand of the blood avenger and return him to his city of refuge, [the place] to which he had escaped; and he shall live there until the death of the high priest who was anointed with the sacred oil.

and the blood avenger finds him outside the border of his city of refuge and kills the offender, the blood avenger will not be guilty of murder,

because the offender should have remained in his city of refuge until the death of the high priest. But after the high priest’s death the offender shall return to the land of his possession.