'Service' in the Bible

They set the priests in their divisions, and the Levites in their courses, for the service of God, which is at Jerusalem; as it is written in the book of Moses.

The vessels that are given to you for the service of the house of your God, deliver before the God of Jerusalem.

and of the Nethinim, whom David and the princes had given for the service of the Levites, two hundred and twenty Nethinim: all of them were mentioned by name.