הַרְנִ֤ינוּ גֹויִם֙ עַמֹּ֔ו כִּ֥י דַם־עֲבָדָ֖יו יִקֹּ֑ום וְנָקָם֙ יָשִׁ֣יב לְצָרָ֔יו וְכִפֶּ֥ר אַדְמָתֹ֖ו עַמֹּֽו
“Praise, O nations, with him, for he will avenge the blood of his servants, and take vengeance on his adversaries; he will be merciful to his land, to his people.”
LXX has an entirely different reading that seems to preserve something missing from MT, but also seems to add something to the text:
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.
“Rejoice, O heavens, together with him, and let all the sons of God worship him. Rejoice, O nations, and let all the angels of God draw near to him. For he will avenge the blood of his sons, and he will take vengeance and repay righteousness to the enemies, and recompense the hated, and the Lord will purify the land of his people.”
The first clause includes the phrase "let all the sons of God worship him" where MT is silent. This seems close to an original reading, closely attested by 4QDeutq, which reads "let all the gods worship him," which is almost identical to Ps 97:7. Q and LXX also have "heavens" against MT's "nations. LXX adds the clause with "nations," however, and provides the parallelism "angels of God" for "sons of God," manifesting the Second Temple Period's conflation of angels and all other divinity attested in the Hebrew Bible (Brenton's version of this verse has "Let all the angels of God worship him," which is quoted verbatim in Heb 1:6). While the "sons of God" were originally conceived of as actual offspring of El, the conflation of Yahweh and El combined with the elevation of Yahweh-El over all the nations and their gods demoted everyone else to the rank of angel, or mere messenger of God. Where MT simply erases the reference to the children of God (or possibly just "gods"), LXX adds a parallel to qualify it. Earlier, in Deut 32:8, LXX interpolates "angels" where Q has "sons" in the phrase "sons of God."
MT also puts "his servants" where LXX and Q have "his sons." It seems quite a bit of manipulation has taken place over the years in this verse. I'm still doing preliminary research, but I've found this verse fascinating. What do you think?