Psalms 2:7
7. The king thus constituted declares the fundamental law of His kingdom, in the avowal of His Sonship, a relation involving His universal dominion.
this day have I begotten thee—as 2Sa 7:14, "he shall be My son," is a solemn recognition of this relation. The interpretation of this passage to describe the inauguration of Christ as Mediatorial King, by no means impugns the Eternal Sonship of His divine nature. In Ac 13:33, Paul's quotation does not imply an application of this passage to the resurrection; for "raised up" in Ac 13:32 is used as in Ac 2:30; 3:22, &c., to denote bringing Him into being as a man; and not that of resurrection, which it has only when, as in Ac 2:34, allusion is made to His death (Ro 1:4). That passage says He was declared as to His divine nature to be the Son of God, by the resurrection, and only teaches that that event manifested a truth already existing. A similar recognition of His Sonship is introduced in Heb 5:5, by these ends, and by others in Mt 3:17; 17:5.Psalms 40:7-8
7. Then—in such case, without necessarily referring to order of time.
Lo, I come—I am prepared to do, &c. in the volume of the book—roll of the book. Such rolls, resembling maps, are still used in the synagogues. written of me—or on me, prescribed to me (2Ki 22:13). The first is the sense adopted by Paul. In either case, the Pentateuch, or law of Moses, is meant, and while it contains much respecting Christ directly, as Ge 3:15; 49:10; De 18:15, and, indirectly, in the Levitical ritual, there is nowhere any allusion to David.6-8. In Paul's view this passage has more meaning than the mere expression of grateful devotion to God's service. He represents Christ as declaring that the sacrifices, whether vegetable or animal, general or special expiatory offerings, would not avail to meet the demands of God's law, and that He had come to render the required satisfaction, which he states was effected by "the offering of the body of Christ" [Heb 10:10], for that is the "will of God" which Christ came to fulfil or do, in order to effect man's redemption. We thus see that the contrast to the unsatisfactory character assigned the Old Testament offerings in Ps 40:6 is found in the compliance with God's law (compare Ps 40:7, 8). Of course, as Paul and other New Testament writers explain Christ's work, it consisted in more than being made under the law or obeying its precepts. It required an "obedience unto death" [Php 2:8], and that is the compliance here chiefly intended, and which makes the contrast with Ps 40:6 clear.
mine ears hast thou opened—Whether allusion is made to the custom of boring a servant's ear, in token of voluntary and perpetual enslavement (Ex 21:6), or that the opening of the ear, as in Isa 48:8; 50:5 (though by a different word in Hebrew) denotes obedience by the common figure of hearing for obeying, it is evident that the clause is designed to express a devotion to God's will as avowed more fully in Ps 40:8, and already explained. Paul, however, uses the words, "a body hast thou prepared me" [Heb 10:5], which are found in the Septuagint in the place of the words, "mine ears hast thou opened." He does not lay any stress on this clause, and his argument is complete without it. It is, perhaps, to be regarded rather as an interpretation or free translation by the Septuagint, than either an addition or attempt at verbal translation. The Septuagint translators may have had reference to Christ's vicarious sufferings as taught in other Scriptures, as in Isa 53:4-11; at all events, the sense is substantially the same, as a body was essential to the required obedience (compare Ro 7:4; 1Pe 2:24).John 4:34
34. My meat is, &c.—"A Servant here to fulfil a prescribed work, to do and to finish, that is 'meat' to Me; and of this, while you were away, I have had My fill." And of what does He speak thus? Of the condescension, pity, patience, wisdom He had been laying out upon one soul—a very humble woman, and in some respects repulsive too! But He had gained her, and through her was going to gain more, and lay perhaps the foundations of a great work in the country of Samaria; and this filled His whole soul and raised Him above the sense of natural hunger (Mt 4:4).