If he be constant - The conditional character of the promise made to David, as to the continuance of his posterity on the Jewish throne (marginal reference; 2 Samuel 7:14), is now clearly declared.

Moreover, I will establish his kingdom for ever,.... The same is said in 2 Samuel 7:13.

if he be constant to do my commandments, and my judgments, as at this day; if he continued in the observance of them, as he had begun, and went on in until that day; this is added here, and was not spoken by Nathan, when what goes before was; for Solomon was not then born, but must be suggested to David since, and as it should seem at this time.

Moreover I will establish his kingdom for ever, if he be constant to do my commandments and my judgments, as at {c} this day.

(c) If he continues to keep my law as he does now and doesn't depart from it.

28:7 At this day - As he hath begun. This promise is absolute with regard to the Messiah, but conditional, with regard to Solomon. If we are constant in our duty, then and not otherwise, we may expect the continuance of his favour.

constant: Heb. strong

7. I will establish his kingdom for ever, if he be constant to do my commandments-The same condition is set before Solomon by God (1Ki 3:14; 9:4).

28:1-10 During David's last sickness, many chief priests and Levites were at Jerusalem. Finding himself able, David spoke of his purpose to build a temple for God, and of God's disallowing that purpose. He opened to them God's gracious purposes concerning Solomon. David charged them to cleave stedfastly to God and their duty. We cannot do our work as we should, unless we put on resolution, and fetch in strength from Divine grace. Religion or piety has two distinct parts. The first is knowledge of God, the second is worship of God. David says, Know thou the God of thy father, and serve him with a perfect heart and a willing mind. God is made known by his works and word. Revelation alone shows the whole character of God, in his providence, his holy law, his condemnation of sinners, his blessed gospel, and the ministration of the Spirit to all true believers. The natural man cannot receive this knowledge of God. But thus we learn the value of the Saviour's atonement, and of the sanctification of the Holy Spirit, and are influenced to walk in all his commandments. It brings a sinner to his proper place at the foot of the cross, as a poor, guilty, helpless worm, deserving wrath, yet expecting every thing needful from the free mercy and grace of God our Father, and the Lord Jesus Christ. Having been forgiven much, the pardoned sinner learns to love much.