We certify you. The use of the plural is curious. Hitherto the king has made every permission and command to rest on his own sole authority (see Ezra 7:12, Ezra 7:13, Ezra 7:21). Now that he reaches the most important point in the whole of his decree—the permanent exemption of a large part of the people from liability to taxation of any kind, his style changes, and he says, "We certify you."
Perhaps he speaks in the name of himself and his successors; or possibly he means to say that in this matter he has asked and obtained the assent and consent of his council (compare Ezra 7:28). Or ministers.
Rather, "and ministers." It is generally allowed that the word here translated "ministers" is not applied to the Nethinim, but to that still lower grade of attendants in the sanctuary called "Solomon's servants" in Ezra 2:55-58, and Nehemiah 7:57-60.
It shall not be lawful to impose toll, tribute, or custom upon them It may be suspected from this proviso that the Persians exempted from taxation their own (Magian) priests, though of this there is no other evidence.
But they would scarcely have placed a foreign priesthood on a higher level of favour than their own.