LXX Num 25:13

καὶ ἔσται αὐτῶ καὶ τῶ σπέρματι αὐτοῦ μετ’ αὐτὸν διαθήκη ἱερατίας αἰωνία, ἀνθ’ ὧν ἐζήλωσεν τῷ θεῷ αὐτοῦ καὶ ἐξιλάσατο περὶ τῶν υἱῶν ᾿Ισραήλ.

It will be a covenant of permanent priesthood for him and his descendants, because he was zealous for his God and made atonement for the Israelites.”