"tell them when they should keep away from the holy things." Yahweh is about to describe situations where a priest is unclean and not allowed to touch holy things.
The word "profane" here means to dishonor. The word "name" represents Yahweh's character. Alternate translation: "dishonor my reputation" or "dishonor me" (See: [[rc://en/ta/man/translate/figs-metonymy]])