Zechariah 4:10 asks, "Who has despised the day of" what?

Answer: Small things

Encouraging the temple builders, God asked, "Who has despised the day of small things?" Zerubbabel would finish the work.

“For who has despised the day of small things? But these seven eyes of the LORD, which scan the whole earth, will rejoice when they see the plumb line in the hand of Zerubbabel.””— Zechariah 4:10 (BSB)