John Chrysostom, on Heb 9:7

"But into the second the High Priest went alone once every year, not without blood, which he offered for himself, and for the errors of the people." Thou seest that the types were already laid down beforehand? for, lest they should say, "how is there but one sacrifice?" he shows that this was so from the beginning, since at least the more holy and the awful sacrifice was but one. And how did the High Priest offer once for all? Thus were they wont to do from the beginning, for then also (he says) "the High Priest" offered "once for all."

And well said he, "not without blood." (Not indeed without blood, yet not this blood, for the business was not so great.) He signifies that there shall be a sacrifice, not consumed by fire, but rather distinguished by blood. For inasmuch as he called the Cross a sacrifice, though it had neither fire, nor logs, nor was offered many times, but had been offered in blood once for all; he shows that the ancient sacrifice also was of this kind, was offered "once for all" in blood.

"Which he offers for himself;" again, "for himself; and for the errors of the people." He said not "sins"; but "errors," that they might not be high-minded. For even if thou hast not sinned intentionally, yet unintentionally thou hast erred, and from this no man is pure.

And everywhere he adds the "for himself," showing that Christ is much greater. For if He be separated from our sins, how did He "offer for Himself"? Why then saidst thou these things (one says)? Because this is a mark of One that is superior.