Numbers 4:3

From thirty years old and upward even until fifty years old, all that enter into the host, to do the work in the tabernacle of the congregation.

Ver. 3. To do the work.] The work of the ministry is not an idle man's occupation, but a labouring even to lassitude; compared therefore to harvest work, and to that of cleaving wood, digging in mine pits, rowing with oars, &c. All the comfort is, that God that helped the Levites to bear the ark of the covenant, 1Ch 15:26 will not be wanting to his weak, but willing servants, "that labour in the word and doctrine." 1Ti 5:17