Another speaker is next heard, the Anointed King, who, in the third strophe (vv. 7-9), bears witness to Himself and claims universal dominion as His by a Divine decree. "Thou art my son; to-day have I begotten thee." So runs the first part of the decree. The allusion to Nathan's words to David is clear. In them the prophet spoke of the succession of David's descendants, the king as a collective person, so to speak. The psalmist, knowing how incompletely any or all of these had fulfilled the words which were the patent of their kingship, repeats them in confident faith as certain to be accomplished in the Messiah-king, who fills the future for him with a great light of hope. He knew not the historic person in whom the word has to be fulfilled, but it is difficult to resist the conclusion that he had before him the prospect of a king living as a man, the heir of the promises. Now, this idea of sonship, as belonging to the monarch, is much better illustrated by the fact that Israel, the nation, was so named, than by the boasts of Gentile dynasties to be sons of Zeus or Ra. The relationship is moral and spiritual, involving Divine care and love and appointment to office, and demanding human obedience and use of dignity for God. It is to be observed that in our psalm the day of the King's self-attestation is the day of His being "begotten." The point of time referred to is not the beginning of personal existence, but of investiture with royalty. With accurate insight, then, into the meaning of the words, the New Testament takes them as fulfilled in the Resurrection (Acts xiii. 33; Rom. i. 4). In it, as the first step in the process which was completed in the Ascension, the manhood of Jesus was lifted above the limitations and weaknesses of earth, and began to rise to the throne. The day of His resurrection was, as it were, the day of the birth of His humanity into royal glory.
Built upon this exaltation to royalty and sonship follows the promise of universal dominion. Surely the expectation of "the uttermost parts of the earth for a possession" bursts the bonds of the tiny Jewish kingdom! The wildest national pride could scarcely have dreamed that the narrow strip of seaboard, whose inhabitants never entered on any wide schemes of conquest, should expand into a universal monarchy, stretching even farther than the giant empires on either side. If such were the psalmist's expectations, they were never even approximately fulfilled; but the reference of the glowing words to Messiah's kingdom is in accordance with the current of prophetic hopes, and need cause no hesitation to those who believe in prophecy at all.