John Gill Commentary 2 Samuel 7:24

"And thou didst establish to thyself thy people Israel to be a people unto thee for ever; and thou, Jehovah, becamest their God." — 2 Samuel 7:24 (ASV)

For you have confirmed to yourself your people Israel [to be] a
people unto you for ever
So long as they were obedient to him, and observed his laws and statutes, and abode by his worship and ordinances, otherwise he would write a "loammi" on them, as he has, see (Hosea 1:9) ;

and you, Lord, are become their God ;
their covenant God, they having avouched him to be their God, and he having avouched them to be his people, (Deuteronomy 26:17Deuteronomy 26:18) .