Hebrews 7:18

He said that the law undergoes a change, and he demonstrated this. Next he seeks out the reason as well. For we humans find rest only when we learn the reason. And he says: the annulment and rejection of the formerly existing commandment, that is, …

The Levitical priesthood brought nothing to perfection: it could not justify men's persons from guilt; it could not sanctify them from inward pollution; it could not cleanse the consciences of the worshippers from dead works; all it could do was to lead them to the antitype.

For there is implied in this new and everlasting priesthood, and in the new dispensation connected therewith, a disannulling of the preceding commandment - An abrogation of the Mosaic law. For the weakness and unprofitableness thereof - For its insufficiency either to justify or to sanctify.

For there is verily a disannulling of the commandment,....

For there is verily a disannulling - There is a total abrogation, προαγουσης εντολης, of the former law, relative to the Levitical priesthood. See Heb 7:19. For the weakness - It had no energy; it communicated none; it had no Spirit to minister; it required perfect obedience, but furnished no assistance to those who were under it. And unprofitableness - No man was benefited by the mere observance of its precepts: it pardoned no sin, changed no heart, reformed no life; it found men dead in trespasses and sins, and it consigned them to eternal death.

And, as the Levitical priesthood and the law are inseparably joined, since the former is repealed, the latter is so also (see on Heb 7:11). going before--the legal ordinance introducing and giving place to the Christian, the antitypical and permanent end of the former. weakness and unprofitableness--The opposite of "power" (Heb 7:16).

For there is verily a disannulling - A setting aside. The Law which existed before in regard to the priesthood becomes now abrogated in consequence of the change which has been made in the priesthood; see the note at Heb 7:12. Of the commandment - Relating to the office of priest, or to the ceremonial rites in general. This does not refer to the moral law, as if that was abrogated, for: (1) The reasoning of the apostle does not pertain to that, and, (2) That law cannot be abrogated. It grows out of the nature of things, and must be perpetual and universal. Going before - Going before the Christian dispensation and introducing it. For the weakness and unprofitableness thereof - That is, it was not adapted to save man; it had not power to accomplish what was necessary to be done in human salvation. It answered the end for which it was designed - that of introducing a more perfect plan, and then vanished as a matter of course. It did not expiate guilt; it did not give peace to the conscience; it did not produce perfection Heb 7:11, and therefore it gave place to a better system.