Deuteronomy 19:12-13

19:12 The elders of his own city must send for him and remove him from there to deliver him over to the blood avenger ¹  to die. 19:13 You must not pity him, but purge out the blood of the innocent ²  from Israel, so that it may go well with you.

¹ tn The גֹאֵל הַדָּם (go’el haddam, “avenger of blood”) would ordinarily be a member of the victim’s family who, after due process of law, was invited to initiate the process of execution (cf. Num 35:16-28). See R. Hubbard, NIDOTTE 1:789-94.

² sn Purge out the blood of the innocent. Because of the corporate nature of Israel’s community life, the whole community shared in the guilt of unavenged murder unless and until vengeance occurred. Only this would restore spiritual and moral equilibrium (Num 35:33).