Matthew Poole and continuators on Galatians 3:6

6 Even as Abraham believed God , and it was accounted to him for righteousness .

As Abraham was justified, so must all the children of Abraham; but Abraham believed God, (that is, agreed to the truth of all those promises which God gave him, and trusted in God for the fulfilling of them; for both those acts of the mind are included in believing God▪) and so was justified alone.

His Faith it self was not imputed to him; those that put this sense upon the words, either forget that faith it self is a work; or that the Apostle here is arguing for justification by Faith in opposition to justification by works, and cannot be imagined to have gone about to prove that justification is not by works, by proving that it is by a work. The meaning is no more than that he was upon it accounted righteous; not that God so honoured the work of Faith, but that he so rewarded it, as being the condition annexed to the promise of justification. His faith was not his righteousness, but God so rewarded his exercise of Faith, as that upon it he reckoned (or imputed) that to him which was his righteousness, viz. the righteousness of him in whom he believed as revealed unto him in the promise.

Marginal references: Gen. 15.6. Rom. 4.3. Jam. 2.23.; Or, imputed.