These garments belong to the priesthood and are not just Aaron's personal clothing. Alternate translation: "Aaron must reserve the holy garments for his sons after him" (See: [[rc://en/ta/man/translate/figs-activepassive]])
This can be stated in active form. Alternate translation: "They must wear the holy garments when you anoint his sons and ordain them to me" (See: [[rc://en/ta/man/translate/figs-activepassive]])