Deuteronomy 32.43
Septuagint

eufranqhte ouranoi ama autw, 

kai proskunhsatwsan autw 
panteV aggeloi qeou

New Testament - Hebrews 1.6

otan de palin eisagagh ton prwtotokon eiV thn oikoumenhn, legei: 
kai proskunhsatwsan autw 
panteV aggeloi qeou

Septuagint

Rejoice, ye heavens, with him, and let all the angels of God worship him

New Testament

And when he again bringeth in the firstborn into the world, he saith, And let all the angels of God worship him 

Masoretic Text

None

Comments:  The MT simply omits this phrase from Deuteronomy 32.43.  The quotation is similar to the phrase “all gods bow down before him (RSV)” in Psalm 97.7.

(The Septuagint text given above is Brenton's.  Rahlfs' text replaces "angels" with "sons.")

The Dead Sea Scroll 4QDeutq contains a clause similar to that present in the LXX:  “Rejoice, O heavens, together with him; and bow down to him all you gods, for he will avenge the blood of his sons ...”