Hebrews 10:5

For this reason. To show that the sacrifices of the Law were useless, and could not take sins away. He said to God. The quotation is from Psalms 40:6-8 Septuagint. This was a prophecy of how Christ would view the ritual of the Law and his own mission. The point is that the Son's offering of himself is the true sacrifice, which as prophecy shows, God wanted to be made. You do not want the sacrifices and offerings of the Law, because they are weak and useless. But you have prepared. As the Eternal Logos, Christ did not have a body. But the prophecy is that he would come in human form. See 1 John 4:1-3. Jesus had to take our flesh and blood to be able to destroy the Devil (Hebrews 2:14-15 and notes) by dying on the Cross.