'Work of the Lord' in the Bible

He said, "See, I am going to make a covenant before all your people. I will do wonders such as have not been done in all the earth, nor in any nation. All the people among whom you live will see the work of the Lord, for it is a fearful thing that I am doing with you.

and Aaron is to offer the Levites before the Lord as a wave offering from the Israelites, that they may do the work of the Lord.

David said, "Of these, 24,000 are to direct the work of the Lord's temple; 6,000 are to be officials and judges;

So then, dear brothers and sisters, be firm. Do not be moved! Always be outstanding in the work of the Lord, knowing that your labor is not in vain in the Lord.