John Gill Commentary 1 Kings 15:4

"Nevertheless for David`s sake did Jehovah his God give him a lamp in Jerusalem, to set up his son after him, and to establish Jerusalem;" — 1 Kings 15:4 (ASV)

Nevertheless, for David's sake did the Lord his God give him a
lamp in Jerusalem
A kingdom there, as the Targum, splendid and glorious, to be continued in his posterity: to set up his son after him; in it:

and to establish Jerusalem :
to continue that in which the temple was, for the sake of which, and the worship of God in it, there was a succession of David's posterity on the throne of Judah.