13. For next there follows: I will sacrifice unto Thee freely. The sacrifices of the Law, which consisted of whole burnt-offerings and oblations of goats and of bulls, did not involve an expression of free will, because the sentence of a curse was pronounced on all who broke the Law. Whoever failed to sacrifice laid himself open to the curse. And it was always necessary to go through the whole sacrificial action because the addition of a curse to the commandment forbad any trifling with the obligation of offering. It was from this curse that our Lord Jesus Christ redeemed us, when, as the Apostle says: Christ redeemed us from the curse of the law, being made curse for us, for it is written: cursed is every one that hangeth on a tree Gal. iii. 13.. Thus He offered Himself to the death of the accursed that He might break the curse of the Law, offering Himself voluntarily a victim to God the Father, in order that by means of a voluntary victim the curse which attended the discontinuance of the regular victim might be removed. Now of this sacrifice mention is made in another passage of the Psalms: Sacrifice and offering thou wouldest not, but a body hast thou prepared for Me Ps. xxxix. (xl.) 7.; that is, by offering to God the Father, Who refused the legal sacrifices, the acceptable offering of the body which He received. Of which offering the holy Apostle thus speaks: For this He did once for all when He offered Himself up Heb. vii. 27., securing complete salvation for the human race by the offering of this holy, perfect victim.