'Offices' in the Bible

He appointed, according to the ordinance of David his father, the divisions of the priests to their service, and the Levites to their offices, to praise, and to minister before the priests, as the duty of every day required; the doorkeepers also by their divisions at every gate: for so had David the man of God commanded.

besides those who were reckoned by genealogy of males, from three years old and upward, even everyone who entered into the house of Yahweh, as the duty of every day required, for their service in their offices according to their divisions;

and those who were reckoned by genealogy of the priests by their fathers' houses, and the Levites from twenty years old and upward, in their offices by their divisions;

He set the priests in their offices, and encouraged them to the service of the house of Yahweh.