Mark 13:34 "It is like a man, traveling to another country, having left his house, and given authority to his servants, and to each one his work, and also commanded the doorkeeper to keep watch. (See NAS)
Numbers 8:26 but shall minister with their brothers in the Tent of Meeting, to perform the duty, and shall do no service. You shall do thus to the Levites concerning their duties." (See RSV)