Charles Ellicott Commentary 1 Chronicles 28:7

"And I will establish his kingdom for ever, if he be constant to do my commandments and mine ordinances, as at this day." — 1 Chronicles 28:7 (ASV)

Moreover I will establish his kingdom for ever. —This is also found in 1 Chronicles 22:10 (at the end).

If he be constant to do my commandments and my judgments. —The same condition is attached to the same promise in 1 Kings 9:4–5. (Compare also 1 Kings 3:14, where the promise is length of days.)

As at this day. —As we are doing in our present work. The same words occur in the same sense at the end of Solomon’s Prayer (1 Kings 8:61).