Numbers 18:7

And within the vail. — i.e., the vail which separated the holy place from the most holy. The word which is employed in this place (parocheth) is used only of the second vail. (See Leviticus 16:12.) When the outer vail or hanging is designed to be understood, the word used is masak. The reference appears to be to the whole of the priestly duties which were discharged by Aaron and his sons, from those connected with the altar of burnt offering to those which were performed in the most holy place.