7:8 My servant - Lest David should be too much discouraged, or judge himself neglected of God, as one thought unworthy of so great an honour, God here gives him the honourable title of his servant, thereby signifying that he accepted of his service, and good intentions.
7:4-17 Blessings are promised to the family and posterity of David. These promises relate to Solomon, David's immediate successor, and the royal line of Judah. But they also relate to Christ, who is often called David and the Son of David. To him God gave all power in heaven and earth, with authority to execute judgment. He was to build the gospel temple, a house for God's name; the spiritual temple of true believers, to be a habitation of God through the Spirit. The establishing of his house, his throne, and his kingdom for ever, can be applied to no other than to Christ and his kingdom: David's house and kingdom long since came to an end. The committing iniquity cannot be applied to the Messiah himself, but to his spiritual seed; true believers have infirmities, for which they must expect to be corrected, though they are not cast off.