Theophylact of Ohrid

Do you see that the sacrifices were rejected even before the incarnation? For after You rejected the sacrifices, then I — Christ — said: "Behold, I come... to do Your will." And the will of God the Father is that the Son be slain for the world, so that people might be justified, not through sacrifices, but through the death of His Son. For, He says, "I proclaimed Your righteousness in the great assembly" (Ps. 39:10). …

Commentary on Hebrews ↗

Oecumenius

For the Holy Spirit and the power of the Most High overshadowed the Virgin. (Luke 1:35) And it was said, that I may do your will, O Father (Jn. 6:38); that those whom you have given me, I may not lose any of them. (Jn. 18:9) The title of the book, the Hebrews say, is the Law. Isaiah, teaching about the mystery of the Incarnation of the Only Begotten, heard; "Write for me in it with a man's pen." (Isa. 8:1) That it is a sacrifice and offering. Do you see that the sacrifices were cast aside even before the incarnation? …

The Pseudo-Oecumenian Catena on Hebrews ↗

Thomas Aquinas

489. – Then when he says, then said I: Lo, I come, he continues to approve the New Testament. According to a Gloss it is read in the following way: Then, namely, when you did prepare a body for me, i.e., in the conception, I said: Lo, I come, i.e., I propose to come, namely, to the passion: 'This is he that came by water and blood, Jesus Christ' (1 Jn. 5:6). …

Commentary on Hebrews ↗