The Jews had returned from Babylonian captivity, but things were not going so well, especially as they tried to rebuild the temple.
However, the Lord promised them that even as Zerubbabel had laid the foundation, so he would finish the job, and to give them assurance of that, the Lord said,
“For who has despised the day of small things? For these seven rejoice to see the plumb line in the hand of Zerubbabel. They are the eyes of the LORD, which scan to and fro throughout the whole earth” (Zechariah 4:10).
What seemed small to man, was not small to the Lord, and so He would do whatever it took to see the plumb line in Zerubbabel’s hand.
The eyes of the Lord were watching everything, scanning the whole earth, and He was working on behalf of His people for them to get done what He wanted done.
If you are busy doing the Lord’s work, do not think that small things are insignificant, such as a greeting you give someone, or a short prayer you utter, or whatever, because in the sight of the Lord, He can take those small things and build great things.