I have surely built thee a house - He was now fully convinced that the thing pleased God, and that he had taken this place for his settled habitation.

I have surely built thee an house to dwell in, a settled place for thee to abide in for (f) ever.
(f) He spoke according to the tenor of God's promise which was on the condition that they served him correctly.

I have surely built thee an house to dwell in,.... Turning himself from the priests and people, he quieted with a few words, he addressed the Lord; having built an house for him, for his worship and glory, with this view, that he might dwell in it, he was now, by the above token, fully assured it would be an habitation for him:
a settled place for thee to abide in for ever; which is observed in distinction from the tabernacle of Moses, which was often removed from place to place, otherwise this did not continue for ever; though Solomon might hope it would, at least unto the times of the Messiah; and indeed such a building on this spot, for such use, did continue so long, excepting the interval of the seventy years' captivity in Babylon.

I have surely built thee an house--This is an apostrophe to God, as perceiving His approach by the cloud, and welcoming Him to enter as guest or inhabitant of the fixed and permanent dwelling-place, which, at His command, had been prepared for His reception.