Albert Barnes Commentary Hebrews 10:6

"In whole burnt offerings and [sacrifices] for sin thou hadst no pleasure:" — Hebrews 10:6 (ASV)

In burnt offerings and sacrifices for sin you have had no pleasure. This is not quoted literally from the Psalm, but its sense is retained. The reading there is, burnt-offering and sin-offering have you not required. The quotation by the apostle is taken from the Septuagint, with the change of a single word, which does not materially affect the sense—the word ouk eudokesas—"you have no pleasure," instead of ouk ethelesas—"you do not will." The idea is that God had no pleasure in them when compared with obedience.

He preferred the latter, and they could not take its place or serve the same purpose. When they were performed with a pure heart, He was doubtless pleased with the offering. As used here in reference to the Messiah, the meaning is that they would not be what was required of him. Such offerings would not achieve the purpose for which He was sent into the world, for that purpose was to be accomplished only by His being obedient unto death.