Matthew Poole and continuators on Hebrews 7:18

18 For there is verily a disannulling of the commandment going before , for the weakness and unprofitableness thereof .

The Spirit having proved the disannulling of the Aaronical Priesthood for its Imperfection, proceeds to prove the Abolishing of the Law or Covenant annexed to it, like it for weakness and unprofitableness; [non-Latin text not transcribed] is a displacing, deposing or laying it aside as to its binding force, so as there is no Obligation from it on any as to Obedience or Penalty; and this is so disannulled of the Law-maker, God himself, by setting up the Gospel by his Son Priest, which is most certainly true.

For the Mosaical Covenant and Law wanted strength to bring about what the Iews sought by it, and wanted good Fruit to them who made their boast of it, both which weakness and unprofitableness arose from the Hebrews abuse of it, expecting Expiation and Sanctification by it, without minding the Promise which preceded it 430 years, to which it should have led them, and by its neglect proved so fatal to them. For they would be justified and saved by an external Obedience to this Law, without any regard to Christ and his Sacrifice, by whom alone it could be attained, Gal. 3.17, to 27. It was strong and profitable to the end for which God made it to lead to Christ, but weak and unprofitable to justifie or sanctifie them without him, which was the end they use it for, or rather abused it.

Marginal references: Gal. 4.9.