Background
There's a well known textual variant between the MT and LXX readings of Deuteronomy 32:43:
εὐφράνθητε, οὐρανοί, ἅμα αὐτῷ, καὶ προσκυνησάτωσαν αὐτῷ πάντες ἄγγελοι Θεοῦ· εὐφράνθητε, ἔθνη μετὰ τοῦ λαοῦ αὐτοῦ, καὶ ἐνισχυσάτωσαν αὐτῷ πάντες υἱοὶ Θεοῦ· ὅτι τὸ αἷμα τῶν υἱῶν αὐτοῦ ἐκδικᾶται, καὶ ἐκδικήσει καὶ ἀνταποδώσει δίκην τοῖς ἐχθροῖς καὶ τοῖς μισοῦσιν ἀνταποδώσει, καὶ ἐκκαθαριεῖ Κύριος τὴν γῆν τοῦ λαοῦ αὐτοῦ.
Be glad, O skies, with him, and let all the divine sons do obeisance to him. Be glad, O nations, with his people, and let all the angels of God prevail for him. For he will avenge the blood of his sons and take revenge and repay the enemies with a sentence, and he will repay those who hate, and the Lord shall cleanse the land of his people. (NETS)
The LXX reading is closer to the 4QDeut manuscript from Qumran with several changes. The MT (and interestingly the Samaritan Pentateuch) very clearly dropped a reference to 'gods' found in 4QDeut.
Question
Who is the referent of 'him' who the angels are told to worship in this passage? Is the referent the same throughout the entire verse?