'Duties' in the Bible

Now according to the ordinance of his father David, he appointed the divisions of the priests for their service, and the Levites for their duties of praise and ministering before the priests according to the daily rule, and the gatekeepers by their divisions at every gate; for David the man of God had so commanded.

without regard to their genealogical enrollment, to the males from thirty years old and upward—everyone who entered the house of the Lord for his daily obligations—for their work in their duties according to their divisions;

as well as the priests who were enrolled genealogically according to their fathers’ households, and the Levites from twenty years old and upwards, by their duties and their divisions.