Then said he, [lo], I come to do thy will, O God
(See Gill on Hebrews 10:7)
he taketh away the first, that he may establish the second;
the sense is, either that God has taken away, and abolished the law, that he might establish the Gospel; or he has caused the first covenant to vanish away, that place might be found for the second, or new covenant; or he has changed and abrogated the priesthood of Aaron, that he might confirm the unchangeable priesthood of Christ; or rather he has taken away that which was first spoken of in the above citation, namely, sacrifice, offering, burnt offerings, and sin offerings; these he has removed and rejected as insignificant and useless, that he might establish what is mentioned in the second place; namely, the will of God, which is no other than the sacrifice of Christ, offered up according to the will of God, and by which his will is done.