Jamieson, Fausset and Brown on Haggai 2:18

18. Resumed from Hag 2:15 after Hag 2:16, 17, that the blessing in Hag 2:19 may stand in the more marked contrast with the curse in Hag 2:16,17. Affliction will harden the heart, if not referred to God as its author [Moore].

even from the day that the foundation of ... temple was laid--The first foundation beneath the earth had been long ago laid in the second year of Cyrus, 535 B.C. (Ezr 3:10, 11); the foundation now laid was the secondary one, which, above the earth, was laid on the previous work [Tirinus]. Or, translate, "From this day on which the temple is being begun," namely, on the foundations long ago laid [Grotius]. Maurer translates, "Consider ... from the four and twentieth day ... to (the time which has elapsed) from the day on which the foundation ... was laid." The Hebrew supports English Version.