C. F. Keil and Franz Delitzsch on 2 Chronicles 3:3

2Ch 3:3 “And this is Solomon’s founding, to build the house of God;” i.e., this is the foundation which Solomon laid for the building of the house of God. The infin. Hoph. הוּסד is used here and in Ezr 3:11 substantively. The measurements only of the length and breadth of the building are given; the height, which is stated in 1Ki 6:2, is omitted here. The former, i.e., the ancient measurement, is the Mosaic or sacred cubit, which, according to Eze 40:5 and Eze 43:13, was a handbreadth longer than the civil cubit of the earlier time; see on 1Ki 6:2.