John Calvin Commentary Hebrews 8:1

"Now in the things which we are saying the chief point [is this]: We have such a high priest, who sat down on the right hand of the throne of the Majesty in the heavens," — Hebrews 8:1 (ASV)

Now of the things, etc. So that readers might understand the subject he is addressing, he reminds them that his objective is to prove that Christ’s priesthood, by which the priesthood of the law had been abolished, is spiritual. He indeed continues with the same argument; but since he argues using various lines of reasoning, he introduced this reminder, so that he might keep his readers focused on his main point.

He has already shown that Christ is a high priest; he now argues that His priesthood is celestial. From this it follows that by His coming, the priesthood established by Moses under the law was annulled, because it was earthly.

And since Christ suffered in the humble condition of His flesh, and having taken the form of a servant, made himself of no reputation in the world (Philippians 2:7), the Apostle reminds us of His ascension. By this ascension, not only was the shame of the cross removed, but also that lowly and humble condition He had assumed together with our flesh.

For it is by the power of the Spirit, which was gloriously revealed in Christ's resurrection and ascension, that the dignity of His priesthood is to be assessed. He then reasons as follows: “Since Christ has ascended to the right hand of God, so that He might reign gloriously in heaven, He is not the minister of the earthly but of the heavenly sanctuary.”