Psalms 40:8

To do thy will - God willed not the sacrifices under the law, but he willed that a human victim of infinite merit should be offered for the redemption of mankind. That there might be such a victim, a body was prepared for the eternal Logos, and in that body he came to do the will of God; that is, to suffer and die for the sins of the world.

1. Hence we see that the sovereign Will of God is that Jesus should be incarnated; that he should suffer and die; or, in the apostle's words, taste death for every man; that all should believe on him, and be saved from their sins; for this is the Will of God, our sanctification.

2. And as the apostle grounds this on the words of the Psalm, we see that it is the Will of God that that system shall end; for as the essence of it is contained in its sacrifices, and God says he will not have these, and has appointed the Messiah to do his will, i.e., to die for men, hence it necessarily follows, from the psalmist himself, that the introduction of the Messiah into the world is the abolition of the law; and that his sacrifice is that which shall last for ever.

I delight to do thy will, O my God - To wit, in obeying the law; in submitting to all the trials appointed to me; in making an atonement for the sins of men. See the notes at Hebrews 10:7. Compare Philippians 2:8; Matthew 26:39.

Yea, thy law is within my heart - Margin, "In the midst of my bowels." So the Hebrew. The idea is, that the law of God was within him. His obedience was not external, but proceeded from the heart. How true this was of the Redeemer it is not necessary here to say.

40:8 I delight - This is eminently true, of Christ, and is here observed as an act of heroic obedience, that he not only resolved to do, but delighted in doing the will of God, or what God had commanded him, which was to die, and that a most shameful, and painful, and cursed death.My heart - I do not only understand it, but receive it with heartiest love, delighting both to meditate of it, and to yield obedience to it.