But the author of Hebrews by pulling Psalm 40:6 forward and placing it in this context, creates a near seismic event. When paired with all else he has said about the Law and the Old Covenant. The notion that God was not pleased with the sacrifices that He commanded is significant news.
All of these arguments are building an overwhelming case that there is salvation in no other system. There is nothing that we can do to please God, even following His Law, it just cleanses the flesh (9:13), and reminds of sin (10:3).
It is only Christ’s sacrifice that makes us perfect. Our hearts and conscience cleansed (10:22). Perfected for all time (10:14).
There is no other way to enter into relationship with the Lord.
No other avenue that will give Him pleasure with us.
Don’t skim. Study it all.