Ezra 7:24

Also we certify you, that touching any of the priests and
Levites, singers, porters, Nethinims, or ministers of this house of
God
The king had a right and perfect knowledge of the distinct offices and services of those persons, see ( Ezra 7:7 ) ,

it shall not be lawful to impose toll, tribute, or custom, upon them;
that they might be the less encumbered with the affairs of life, and be more at leisure to attend divine service, and do it the more readily and freely; it was usual with the Heathens to except ecclesiastics from taxes, tributes, and imposts; so the priests in Egypt ^F23, and the Druids here in Britain ^F24.