As I was reading Psalm 40 this morning I was struck by verses 6-10:
6Sacrifice and offering you did not desire, but my ears you have pierced
burnt offerings and sin offerings you did not require.
7Then I said, “Here I am, I have come– it is written about me in the scroll.
8I desire to do your will, O my God; your law is within my heart.”
9I proclaim righteousness in the great assembly;
I do not seal my lips, as you know, O LORD.
10I do not hide your righteousness in my heart; I speak of your faithfulness and salvation.
I do not conceal your love and your truth from the great assembly.
The ESV Study Bible has a brief but important comment on these verses: “These verses are part of the OT corrective to any who think that the sacrificial system worked automatically, apart from expressing faith, repentance, and obedience (cf. 50:8-15; 51:16-19; Prov. 14:9; Isa. 1:11-17).” [It would be worth your time to follow the cross references.]
The Study Bible also points us to the great cross reference in Hebrews 10 in which these rather odd sounding verses are applied directly to Jesus, and in the context of His ministry they make perfect sense. In other words, these verses are prophetic of Jesus, as are so many others in the Psalms.
Here is the text from Hebrews, although you have to recognize that the author of Hebrews has been building toward this conclusion at least from chapter 7:
Hebrews 10:1-18 (NIV) 1The law is only a shadow of the good things that are coming–not the realities themselves. For this reason it can never, by the same sacrifices repeated endlessly year after year, make perfect those who draw near to worship. 2If it could, would they not have stopped being offered? For the worshipers would have been cleansed once for all, and would no longer have felt guilty for their sins. 3But those sacrifices are an annual reminder of sins, 4because it is impossible for the blood of bulls and goats to take away sins. 5Therefore, when Christ came into the world, he said:
“Sacrifice and offering you did not desire, but a body you prepared for me;
6with burnt offerings and sin offerings you were not pleased.
7Then I said, ‘Here I am–it is written about me in the scroll– I have come to do your will, O God.'”
8First he said, “Sacrifices and offerings, burnt offerings and sin offerings you did not desire, nor were you pleased with them” (although the law required them to be made). 9Then he said, “Here I am, I have come to do your will.” He sets aside the first to establish the second. 10And by that will, we have been made holy through the sacrifice of the body of Jesus Christ once for all.
11Day after day every priest stands and performs his religious duties; again and again he offers the same sacrifices, which can never take away sins. 12But when this priest had offered for all time one sacrifice for sins, he sat down at the right hand of God. 13Since that time he waits for his enemies to be made his footstool, 14because by one sacrifice he has made perfect forever those who are being made holy. 15The Holy Spirit also testifies to us about this. First he says: 16″This is the covenant I will make with them after that time, says the Lord. I will put my laws in their hearts, and I will write them on their minds.” 17Then he adds: “Their sins and lawless acts I will remember no more.” 18And where these have been forgiven, there is no longer any sacrifice for sin.