# after the mildewed item was washed

This can be translated in active form. Alternate translation: "after they washed the mildewed item" (See: [[rc://en/ta/man/translate/figs-activepassive]])

# it is unclean

Something that God has declared to be unfit for people to touch is spoken of as if it were physically unclean. (See: [[rc://en/ta/man/translate/figs-metaphor]])

# You must burn the item

Here "you" does not refer to the priest specifically. It just means someone must burn the object.