Deuteronomy 32:43

And when all had given assent, I said: “I would now adduce some passages which I had not recounted before. They are recorded by the faithful servant Moses in parable, and are as follows: ‘Rejoice, O ye heavens, with Him, and let all the angels of God worship Him;’ ” and I added what follows of the passage: “ ‘Rejoice, O ye nations, with His people, and let all the angels of God be strengthened in Him: for the blood of His sons He avenges, and will avenge, and will recompense His enemies with vengeance, and will recompense those that hate Him; and the Lord will purify the land of His people.’ And by these words He declares that we, the nations, rejoice with His people, to wit, Abraham, and Isaac, and Jacob, and the prophets, and, in short, all of that people who are well-pleasing to God, according to what has been already agreed on between us. …

Ver. 10-12 . “And, rejoice, ye Gentiles, with His people. And, Praise the Lord, all ye Gentiles” ( Deut. xxxii. 43 ); “and let all people laud Him.” ( Ps. cxvii. 1 .) “And, There shall be a root of Jesse, and He that shall rise to reign over the Gentiles, in Him shall the Gentiles trust.” ( Is. xi. 1, 10 .) Now all these quotations he has given to show that we ought to be united, and to glorify God; and also, to humble the Jew, that he may not lift himself up over these, since all the prophets called these, as well as to persuade the man of the Gentiles to be lowly, by showing him that he had a larger grace to answer for. Then he concludes his argument with a prayer again.

But to men who meditate on God’s law day and night, it is indeed needless to write all the proofs of this kind; the above are sufficient to persuade even the most obstinate opponents not to divide the divine titles. One point, however, I cannot endure to omit. He is alleged to have said that there are many Christs but one Son. Into this error I suppose he fell through ignorance. For if he had read the divine Scripture, he would have known that the title of the Son has also been bestowed by our bountiful Lord on many. …

33. Continue your study of the witness borne by Moses; mark how diligently he seizes every opportunity of proclaiming the Lord and God. You take note of the passage, Hear, O Israel, the Lord thy God is One . Note also the words of that Divine song of his; See, See, that I am the Lord, and there is no God beside Me. While God has been the Speaker throughout the poem, he ends with, Rejoice, ye heavens, together with Him and let all the sons of God praise Him. Rejoice, O ye nations, with His people, and let all the Angels of God do Him honour . God is to be glorified by the Angels of God, and He says, For I am the Lord, and there is no God beside Me . For He is God the Only-begotten, and the title ‘Only-begotten’ excludes all partnership in that character, just as the title ‘Unoriginate’ denies that there is, in that regard, any who shares the character of the Unoriginate Father. …

36. The true method of our enquiry demands that we should begin with him, through whom God first manifested Himself to the world, that is, with Moses, by whose mouth God the Only-begotten thus declared Himself; See, see that I am God, and there is no God beside Me . That godless heresy must not assign these words to God, the unbegotten Father, is clear by the sense of the passage and by the evidence of the Apostle who, as we have already stated, has taught us to understand this whole discourse as spoken by God the Only-begotten. The Apostle also points out the words, Rejoice, O ye nations, with His people as those of the Son, and in corroboration further cites this: And there shall be a root of Jesse, and One that shall arise to rule the nations; in Him shall the nations trust . …