In the Septuagint these very words occur in Deut. 32:43, where they are inserted in the Song of Moses. But they are not in the Hebrew; nor are they in all the copies of the Septuagint . The Hebrew is, "Rejoice, O ye nations, with his people; for he will avenge the blood of his servants, and will render vengeance to his adversaries.", The Septuagint is, "Rejoice ye heavens with him and let all the angels of God worship him. Let the nations rejoice with his people, and let all the sons of God be strong in him, for he has avenged the blood of his sons."
Consider these thoughts:
1. The passage is not in the Hebrew; and it seems hardly credible that, in writing to Hebrews, and to those residing in the very country where the Hebrew Scriptures were constantly used, he should make reference to, as a proof-text on an important doctrine, what was not in their Scriptures.
2. It is omitted in all the ancient versions, except the Septuagint, and then, not 100% agreement.
3. The passage in question, in Deuteronomy, does not contain any reference to the Messiah. It does not relate to His "introduction" to the world. It would not occur to any reader that it had any such reference. The context celebrates the victory over the enemies of Israel which God will achieve. After saying that "his arrows would be drunk with blood, and that his sword would devour flesh with the blood of the slain and of captives, from the time when he begins to take vengeance on an enemy," the Septuagint (not the Hebrew) immediately asserts, "let the heavens rejoice at the same time with him, and let all the angels of God worship him." That is: "Let the inhabitants of the heavenly world rejoice in the victory of God over the enemies of his people, and let them pay their adoration to him." But the Messiah does not appear to be alluded to anywhere in the context; much less described as "introduced into the world."
The probability is, that the writer here referred to Ps 97:7 "Confounded be all they that serve graven images, that boast themselves of idols: worship him, all ye gods."
-from Albert Barnes NT Commentary.