Matthew Poole and continuators on Hebrews 10:8

8 Above when he said, Sacrifice, and offering, and burnt-offerings, and offering for sin thou wouldest not, neither hadst pleasure therein, (which are offered by the Law:)

In this Verse the Apostle repeats the whole Testimony, produced out of the Psalm only with a Specification in a Parenthesis; which are offered by the Law, viz. such Sacrifices, against which the Apostle argueth, which could not purge away Sin, nor procure Righteousness, nor make no more Conscience of Sins. He observes from the Psalm, that the Will of God was plainly signified by his Spirit to David under the Law, about the Nature, State and Design of his Institution of Sacrifices, that they were typical of, and leading to a better Sacrifice than themselves; and that for their own sake only, they were no way acceptable to God, and so rejected by him.