John Gill Commentary 2 Chronicles 35:2

"And he set the priests in their offices, and encouraged them to the service of the house of Jehovah." — 2 Chronicles 35:2 (ASV)

And he set the priests in their charges
In their offices, and in their proper places, to execute them:

and encouraged them to the service of the house of the Lord ;
to attend it with cheerfulness and constancy, and do it according to the will of God, promising his favour and protection.