Albert Barnes Commentary 1 Kings 9:3

"And Jehovah said unto him, I have heard thy prayer and thy supplication, that thou hast made before me: I have hallowed this house, which thou hast built, to put my name there for ever; and mine eyes and my heart shall be there perpetually." — 1 Kings 9:3 (ASV)

The answer given by God to Solomon’s prayer is reported more fully in 2 Chronicles 7:12–22.

When God puts His name in the temple, He does it with the intention that it be there “forever.” He will not arbitrarily withdraw it; as far as God is concerned, it will remain there “forever.” But the people may drive it away by their unfaithfulness (1 Kings 9:7–9).

And my eyes and my heart — This is an answer that exceeds the prayer in 1 Kings 8:29. The promise is not “my eyes only, but my eyes and my heart.”