According to the author of the book, this verse talks about special angel-like figures called cherubims with big wings that were placed in a holy part of the temple. Their wings were so wide that they touched the walls and met in the middle, showing how grand and important this place was.
1 Kings 6:27: And he set the cherubims within the inner house: and they stretched forth the wings of the cherubims, so that the wing of the one touched the [one] wall, and the wing of the other cherub touched the other wall; and their wings touched one another in the midst of the house. [they...: or, the cherubims stretched forth their wings]
1 Kings 6:27 describes cherubims within a physical temple, whereas 1 Kings 8:27 emphasizes that the heavens, even the highest heaven, cannot contain God, questioning the necessity of a physical temple.
1 Kings 8:27: But will God indeed dwell on the earth? behold, the heaven and heaven of heavens cannot contain thee; how much less this house that I have builded?