Genesis 15:6 - Ellicott's Commentary On The Whole Bible

He believed in the Lord (in Jehovah)... — We have here the germ of the doctrine of free justification. Abram was both a holy man and one who proved his faith by his works; but nevertheless the inspired narrator inserts this reflection, not after the history of the offering of Isaac, but in the account of this vision, where all that Abram did was to believe, and for that belief’s sake was accounted righteous before God. For the definite conclusions deduced from this verse by St. Paul see Romans 4. The quotation there is from the LXX., and gives the general sense, but the correct rendering of the Hebrew is that given in our version.