For the priesthood being changed, there is made of necessity a change also of the law. The priesthood being changed - That is, The order of Aaron being now abrogated, to make way for that which had preceded it, the order of Melchisedec.
There is made of necessity a change also of the law - The very essence of the Levitical law consisting in its sacrificial offerings; and as these could not confer perfection, could not reconcile God to man, purify the unholy heart, nor open the kingdom of heaven to the souls of men, consequently it must be abolished, according to the order of God himself; for he said, Sacrifice and offering, and burnt-offering, and sacrifice for sin, he would not; see Psalms 40:6, Psalms 40:7, compared with Hebrews 10:5-10, and with Psalms 110:4, where it is evident God designed to change both the law and the priesthood, and to introduce Jesus as the only Priest and Sacrifice, and to substitute the Gospel system for that of the Levitical institutions. The priesthood, therefore, being changed, Jesus coming in the place of Aaron, the law of ordinances and ceremonies, which served only to point out the Messiah, must of necessity be changed also.