'Office' in the Bible

For the Levites left their suburbs and their possession, and came to Judah and Jerusalem: for Jeroboam and his sons had cast them off from executing the priest's office unto the LORD:

Now it came to pass, that at what time the chest was brought unto the king's office by the hand of the Levites, and when they saw that there was much money, the king's scribe and the high priest's officer came and emptied the chest, and took it, and carried it to his place again. Thus they did day by day, and gathered money in abundance.

And next him were Eden, and Miniamin, and Jeshua, and Shemaiah, Amariah, and Shecaniah, in the cities of the priests, in their set office, to give to their brethren by courses, as well to the great as to the small:

And to the genealogy of all their little ones, their wives, and their sons, and their daughters, through all the congregation: for in their set office they sanctified themselves in holiness: