Calvin's Commentaries, Vol. 4: Harmony of the Law, Part II, tr. by John King, [1847-50], at sacred-texts.com
36. And thou shalt offer every day a bullock for a sin-offering for atonement: and thou shalt cleanse the altar, when thou hast made an atonement for it, and thou shalt anoint it, to sanctify it.
36. Juvencum pro peccato facies in singulos dies pro expiationibus: et expiabis altare expiando ipsum, ungesque illud ad ipsum sanctificandum.
37. Seven days thou shalt make an atonement for the altar, and sanctify it; and it shall be an altar most holy: whatsoever toucheth the altar shall be holy.
37. Septem diebus expiabis altare et sanctificabis illud: eritque sanctitas sanctitatum: quicquid tetigerit altare, sanctificabitur.
36. And thou shalt offer every day a bullock. Since the ancient altar was no less a type of Christ than the priest was, it may naturally be asked, what its expiation could mean, as if there were anything impure or polluted in Christ. But we must remember, what I before adverted to, that no similitude is identical (with the reality); for then the substance and reality of the shadows could not be represented in their perfection. Yet this was an apt similitude, shewing that God could only be propitiated towards the human race by an expiation made with blood. On this account not only was the altar to be cleansed, but; also dedicated to its use, that reconciliation might proceed from it; and this is expressed by the word “sanctify,” especially when it is added, “it shall be the holiness of holinesses,” 151 that it may sanctify whatever is put upon it. Others read it in the masculine gender: “Whosoever shall touch it, shall be holy;” and understand it of the priest, who by right of his anointing might approach the altar; but; it rather dignifies the consecration of the altar by its consequence, viz., because it sanctifies the victims themselves. The sum is that the body of Christ, inasmuch as it was offered as a sacrifice, and consecrated with blood, was acceptable to God; so that its holiness washes away and blots out all our uncleanness. We shall speak of the anointing a little further on.
A.V., “And it shall be an altar most holy.” Ainsworth, in loco, says: “Heb. holinesse of holinesses; i.e., most holy, not only sanctified itself, but sanctifying the gifts that were offered to God upon it."