John Calvin Commentary Exodus 40:9

"And thou shalt take the anointing oil, and anoint the tabernacle, and all that is therein, and shalt hallow it, and all the furniture thereof: and it shall be holy." — Exodus 40:9 (ASV)

And you shall take the anointing oil. There was by no means any inherent power or efficacy for sanctification in the oil, except insofar as it was a type of the Spirit, from whom, as its only source, all holiness originates. Assuredly, the oil, being a perishable liquid, neither penetrates the soul nor would it, by itself, be at all effective for spiritual service. It appears, however, from many passages of Scripture, that it was a symbol of all the gifts of the Holy Spirit.

This figure, therefore, clearly shows that nothing pleases God, and nothing is pure or holy in His sight, except what has been cleansed and properly consecrated by the influence and grace of the Holy Spirit. Moreover, God wanted all the vessels of the sanctuary to be set apart from common use by this sacred anointing. This was so that the Israelites might distinguish between sacred and profane things. In this way, God’s service would receive its due reverence, ensuring that no one would introduce the pollutions of the flesh into that place, the purity of which had been marked by that sacred symbol.

A question, however, arises here: why He dignifies the altar of burnt-offering with a more exalted title? For after calling the tabernacle itself and its vessels simply holy, He calls the altar “holy of holies,” which I have rendered sacrosanctum.

I do not doubt that it acquired this name from the sacrifices, which are also described as such because of the atonement made by them,³⁹⁷ as we have seen elsewhere. The children of Israel, therefore, were taught that God is truly reconciled by whole burnt offerings and burnt offerings, since “the holiness of holinesses” resided on the altar itself.

³⁹⁷ See on Leviticus 6:25, , ante, vol. 2, p. 366..