Here the priests are asking a question in order to state that they have not really polluted Yahweh. This can be expressed as a statement. Alternate translation: "We have not polluted you." or "Tell us how we have polluted you, because we do not think that we have done so." (See: [[rc://en/ta/man/translate/figs-rquestion]])
This is the answer that Yahweh gives to the priests, but the full answer is only implied. This can be made explicit. Alternate translation: "You have polluted my altar by saying, 'Yahweh's table is contemptible.'" (See: [[rc://en/ta/man/translate/figs-ellipsis]])