John Calvin Commentary Hebrews 9:25

"nor yet that he should offer himself often, as the high priest entereth into the holy place year by year with blood not his own;" — Hebrews 9:25 (ASV)

Nor yet that he should offer himself often, etc. How, then, is he a priest, one might say, if he offers no sacrifices?

To this I reply that it is not required of a priest that he should be continually sacrificing. For even under the Law, there were days appointed for the chief sacrifices every year, and they also had their daily hours, morning and evening.

But since that only true sacrifice which Christ offered once for all is always efficacious, and thus perpetual in its effects, it is no wonder that Christ’s eternal priesthood is sustained by its virtue, which never fails.

And here again he shows how and in what things Christ differs from the Levitical priest. He had spoken of the sanctuary before, but he notes one difference regarding the kind of sacrifice: Christ offered himself and not an animal. He adds another difference: that he did not repeat his sacrifice, as under the Law, where the repetition was frequent and even incessant.