For if the inheritance be of the law, it is no more of promise: but God gave it to Abraham by promise.’ If it was ‘by Promise,’ then it was ‘by faith,’ for faith only receives the Promise; if it was by the Law, then it was by works, for works only fulfil the Law. True, the Law was afterwards added to the Promise, but not to disannul or to supersede it; on the contrary, it was itself a dispensation of the covenant of grace, for it was proclaimed in the name of the ‘God of Abraham, and Isaac, and Jacob;’ and if it republished in all their rigour the original terms of the covenant of works, it was only ‘because of transgressions, till the seed should come to whom the Promise was made.’ It was for conviction of sin, for ‘the Law worketh wrath,’ and is a ‘ministration of death;’ but, as such, it was ‘our schoolmaster to bring us unto Christ, that we might be justified by faith.’

—James Buchanan, The Doctrine of Justification: An Outline of Its History in the Church and of Its Exposition from Scripture (Edinburgh: T&T Clark, 1867), 52–53.