Albert Barnes Commentary 2 Chronicles 3:4

"And the porch that was before [the house], the length of it, according to the breadth of the house, was twenty cubits, and the height a hundred and twenty; and he overlaid it within with pure gold." — 2 Chronicles 3:4 (ASV)

The height was one hundred and twenty cubits - This height, which so much exceeds that of the main building (1 Kings 6:2), is probably to be corrected by the reading of the Arabic Version and the Alexandrian Septuagint, “twenty cubits.” But see 2 Chronicles 3:9.