Charles Ellicott Commentary 2 Chronicles 3:11

"And the wings of the cherubim were twenty cubits long: the wing of the one [cherub] was five cubits, reaching to the wall of the house; and the other wing was [likewise] five cubits, reaching to the wing of the other cherub." — 2 Chronicles 3:11 (ASV)

And the wings of the cherubims were twenty cubits long. — Their length was, altogether, twenty cubits; so that, being outspread, they reached from wall to wall of the Holy of holies, which was twenty cubits wide. Of this breadth each cherub covered half, or ten cubits, with his wings, which were five cubits each in length. Obviously the inner wing of each cherub met the inner wing of the other in the middle of the wall.

One wing ... other cherub. — The wing of the one, extending to five cubits, was touching the wall of the chamber, and the other wing — five cubits — was touching the wing of the other cherub.