Charles H. Spurgeon on Psalms 89:19

Then thou spakest in vision to thy holy one. The Psalmist returns to a consideration of the covenant made with David. The holy one here meant may be either David or Nathan the prophet, but most probably the latter, for it was to him that the word of the Lord came by night. 2Sa 7:4-5. God condescends to employ his gracious ministers to be the means of communication between himself and his favoured ones, —even to King David the covenant was revealed by Nathan the prophet; thus the Lord puts honour upon his ministers. I have laid help upon one that is mighty. The Lord had made David a mighty man of valour, and now he covenants to make him the helper and defender of the Jewish state. In a far fuller sense the Lord Jesus is essentially and immeasurably mighty, and on him the salvation of his people rests by divine appointment, while his success is secured by divine strength being engaged to be with him. Let us lay our faith where God has laid our help. I have exalted one chosen out of the people. David was God's elect, elect out of the people, as one of themselves, and elect to the highest position in the state. In his extraction, election, and exaltation, he was an eminent type of the Lord Jesus, who is the man of the people, the chosen of God, and the king of his church. Whom God exalts let us exalt. Woe unto those who despise him, they are guilty of contempt of court before the Lord of Hosts, as well as of rejecting the Son of God.