The directions are given to “Aaron and his sons, and all the children of Israel,” because they were not only binding upon the nation generally, but upon the priesthood also; whereas the instructions in ch. 18-20 are addressed to “the children of Israel,” or “the whole congregation” (Lev 18:2; Lev 19:2; Lev 20:2), just as special laws are laid down for the priests in ch. 20 and 21 with reference to the circumstances mentioned there.