John Gill Commentary 1 Kings 8:18

"But Jehovah said unto David my father, Whereas it was in thy heart to build a house for my name, thou didst well that it was in thy heart:" — 1 Kings 8:18 (ASV)

And the Lord said to David my father
By Nathan the prophet:

whereas it was in your heart to build an house to my name, you
did well that it was in your heart ;
his design was good, and so far it was acceptable to the Lord, that he thought of such a thing, though it was not his pleasure that should do it, as follows.