Psalms 2:7

I will tell of the decree Said David, “This is an established decree, and [one] that I have received to tell this and to make known.”

The Lord said to me through Nathan, Gad, and Samuel.

You are My son The head over Israel, who are called “My firstborn son.” And they will endure through you, as is stated concerning Abner (II Sam. 3:18): “for God said, etc., ‘By the hand of My bondsman David shall I deliver...Israel.’” And for their sake, you are before Me as a son because they are all dependent upon you.

this day have I for I have enthroned you over them.

begotten you to be called My son and to be beloved to Me as a son for their sake, as it is stated (I Chronicles 14:2): ‘And David knew that the Lord had established him as king over Israel, and that his kingdom was highly exalted for the sake of His people Israel.’ And we find that the kings of Israel who were beloved before Him were called sons, as it is stated (II Sam. 7:14) concerning Solomon: “I will be to him a father, and he shall be to Me a son.” We find further concerning David (Ps. 89:27) “He shall call Me, ‘You are my Father, my God, and the Rock of my salvation.’”

Let me tell (אֲסַפְּרָ֗ה - asapperah): These are the words of David along with his prophecy; or, the words of the poet [who composed the psalm] speaking on his [David's, or the Messiah's] behalf.

[Regarding] the decree (אֶֽ֫ל־חֹ֥ק - el chok): [The meaning is:] This which I will tell, I will establish it (asim oto) as a decree (le-chok) that should be related. And this [decree] is: He said to me, "You are My son" – [meaning] to serve HaShem, just as a son honors a father.

I have fathered you this day (אֲ֝נִ֗י הַיּ֥וֹם יְלִדְתִּֽיךָ - ani hayom yelidtíkha): This is similar to (Deuteronomy 32:18): "The Rock who fathered you (tzur yeladkha), you forgot."

Let me declare it for a decree: – This is the utterance of David, who says, I will make this declaration a decree and rule. And what is the declaration? That

The Lord said unto me, Thou art My son: – and the kingdom has come to me from Him, and therefore let no man stir up strife against it, for the Lord hath chosen me for a son, as He said to Samuel (1 Sam. 16:1): “For I have provided among his sons a king for Myself.” It is as though to say, “This king is Mine and he is My son and servant and obeys Me” – for everyone who is obedient in the service of God He calls His son, just as a son obeys his father and is ready for his service. And so (in the verse) “ye are sons of the Lord your God” (Deut. 14:1), and “I will be his Father and he shall be My son” (2 Sam. 7:14); and it says (Hos. 2:1), “the sons of the living God.”

This day have I begotten thee: – The day when he was anointed was the day God took him to Himself for a son, as it says (1 Sam. 16:1), “to Me a king.” And he says, This day have I begotten thee, for on that day there was born in him the spirit of God, as is written (1 Sam. 16:13), “And the spirit of the Lord came mightily upon David from that day and onward.” And from that day onward he gave expression to songs and psalms by the Holy Spirit, which was born in him and imparted to him by God. Moreover, the spirit of might was added to him from that day onward; and so it says (Deut. 32:18), “Of the rock that begat thee thou art unmindful” which made thee great and put wisdom in thine heart and intelligence, in the day of the station at Mount Sinai. And so it says (ibid. 6), “Is not He thy Father that hath bought thee?” For if he had said begotten thee, bought thee in reference to (the act of) creation, this would have been no more true of Israel than the rest of men. Do you not see what he says, “Do ye thus requite the Lord?” (ibid.), meaning, “This is the requital you make Him for all the good He has done to you! Surely He is thy Father who bought thee!” And he says, “Of the rock that begat thee thou art unmindful and hast forgotten the God that gave thee birth” (ibid. 18), just as he says thy Father, for He is to you as a father, and the one that gave thee birth – that is, the mother.