The exact words of 2 Samuel 7 are not reproduced; only their general sense is given. In 1 Kings 8:18, what was merely tacitly implied was regarded as actually “said.”
Related Commentaries of 1 Kings 8:15
1 Kings 8:15
15 And he said, Blessed be the LORD God of Israel, which spake with his mouth unto David my father, and hath with his hand fulfilled it, saying,