Albert Barnes Commentary 1 Kings 8:15

"And he said, Blessed be Jehovah, the God of Israel, who spake with his mouth unto David thy father, and hath with his hand fulfilled it, saying," — 1 Kings 8:15 (ASV)

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.”