After the writer of Hebrews quoted from Psalm 40, he then explained,
“Previously saying, ‘Sacrifice and offering, burnt offerings, and offerings for sin You did not desire, nor had pleasure in them’ (which are offered according to the law), then He said, ‘Behold, I have come to do Your will, O God.’ He takes away the first that He may establish the second” (Hebrews 10:8–9).
God did not desire the slaughter of all those animals during the Law of Moses, and knowing such, when Jesus came to the Earth, He knew fully that the sacrificed needed was His own self.
Therefore, He did not come to do His own will, but to do the will of God. We are disciples of Christ. Should we not say the same thing?