Then said Solomon, The LORD hath said that he would dwell in the thick darkness.

Then Solomon said: The Lord promised that he would dwell in a cloud.

Then Solomon said, O Lord, to the sun you have given the heaven for a living-place, but your living-place was not seen by men,

Then spoke Solomon:

Then Solomon said, 'The LORD has said that he would dwell in the thick cloud.

Compare Kings (marginal references).
Compare Kings (marginal references).

The Lord hath said that he would dwell - Solomon, seeing the cloud descend and fill the house, immediately took for granted that the Lord had accepted the place, and was now present. What occurred now was precisely the same with what took place when Moses reared the tabernacle in the wilderness; see Exodus 40:34, Exodus 40:35 : A cloud covered the tent - and the glory of the Lord filled the tabernacle. And Moses was not able to enter into the tent - because the glory of the Lord filled the tabernacle.
The Chaldee paraphrases thus: "Then said Solomon, It has pleased God to place his majesty in the city of Jerusalem, in the house of the sanctuary which I have built to the name of his Word, and he hath placed a dark cloud before him.

Then (a) said Solomon, The LORD hath said that he would dwell in the thick darkness.
(a) After he had seen the glory of the Lord in the cloud.

See Introduction to Chapter 5

The order of Solomon's prayer is to be observed. First and chiefly, he prays for repentance and forgiveness, which is the chief blessing, and the only solid foundation of other mercies: he then prays for temporal mercies; thereby teaching us what things to mind and desire most in our prayers. This also Christ hath taught us in his perfect pattern and form of prayer, where there is but one prayer for outward, and all the rest are for spiritual blessings. The temple typified the human nature of Christ, in whom dwelleth all the fulness of the Godhead bodily. The ark typified his obedience and sufferings, by which repenting sinners have access to a reconciled God, and communion with him. Jehovah has made our nature his resting-place for ever, in the person of Emmanuel, and through him he dwells with, and delights in his church of redeemed sinners. May our hearts become his resting-place; may Christ dwell therein by faith, consecrating them as his temples, and shedding abroad his love therein. May the Father look upon us in and through his Anointed; and may he remember and bless us in all things, according to his mercy to sinners, in and through Christ.

SOLOMON BLESSES THE PEOPLE AND PRAISES GOD. (2Ch. 6:1-41)
The Lord hath said that he would dwell in the thick darkness--This introduction to Solomon's address was evidently suggested by the remarkable incident recorded at the close of the last chapter: the phenomenon of a densely opaque and uniformly shaped cloud, descending in a slow and majestic manner and filling the whole area of the temple. He regarded it himself, and directed the people also to regard it, as an undoubted sign and welcome pledge of the divine presence and acceptance of the building reared to His honor and worship. He referred not to any particular declaration of God, but to the cloud having been all along in the national history of Israel the recognized symbol of the divine presence (Exodus 16:10; Exodus 24:16; Exodus 40:34; Numbers 9:15; 1-Kings 8:10-11).

The words with which Solomon celebrates this wondrous evidence of the divine favour, entirely coincide with the narrative in 1-Kings 8:12-21, except that in 2-Chronicles 6:5. the actual words of Solomon's speech are more completely given than in 1-Kings 8:16, where the words, "and I have not chosen a man to be prince over my people Israel, and I have chosen Jerusalem that my name might be there," are omitted. For the commentary on this address, see on 1-Kings 8:12-21.

Thick darkness - He has indeed made darkness his pavilion. But let this house be the residence of that darkness. It is in the upper world that he dwells in light, such as no eye can approach.