And the LORD said unto Moses, Speak unto Aaron thy brother, that he come not at all times into the holy place within the vail before the mercy seat, which is upon the ark; that he die not: for I will appear in the cloud upon the mercy seat.
Come not at all times ... Common priests went every day to burn incense on the golden altar into the part of the sanctuary without the veil. But none except the high priest was allowed to enter within the veil (Leviticus 4:6), and that only once a year, with the greatest care and solemnity. "The holy place," for the most holy place (Hebrews 9:2-3): the sacred writers frequently use the positive for the other degrees of comparison. This arrangement was evidently designed to inspire a reverence for the most holy place, and the precaution was necessary, at a time when the presence of God was indicated by sensible symbols, the impression of which might have been diminished or lost by daily and familiar observation.
I will appear in the cloud - i:e., in darkness, according to Bahr, who supposes that the reference is to the dense cloud of fragrant smoke mentioned Leviticus 16:13. But this view of thick impenetrable darkness is contradicted by Exodus 40:34 and Numbers 9:15. Vitringa ('Obs. Sac.,' tom. 1:, pp. 161-171) maintained the same opinion, believing that, while the ark of the covenant was called God's habitation, He was present only in an invisible manner, being known to His people that He was present there by the oracles issued from that sacred crypt. But it is expressly said here, "I will appear х be`aanaan (H6051)] in the cloud," the known cloud by which Yahweh accompanied the Israelites through the desert, and in a condensed form took possession of the tabernacle.
It has, indeed, been a subject of discussion, whether this cloud constantly rested upon the ark, and there is no distinct intimation given upon the subject, although the visible symbol was believed to be there by the later Jews, who gave it the name of shechinah-a bright and glorious halo. But there can be no doubt that at the annual entrance into the adytum, the most holy place, by the high priest, the spiritual presence of God did embody itself in the cloud, as it had formerly done, above the capporeth (see Hengstenberg, 'Christol.,' 2:, pp. 384-386) - i:e., the smoke of the incense which the high priest burnt on his yearly entrance into the most holy place: and this was the cloud which at that time enveloped the mercy seat.