Was not Abraham our father justified by works
Not as the causes of his justification, that is denied, ( Romans 4:2 ) but as effects of it, showing the truth of his faith, and the reality of his justification: he had both faith and works, and the former were known by the latter; and even the faith which he had expressed years ago was manifested, demonstrated, and confirmed to be true and genuine, by the instance of his obedience to God, here produced; by which it appeared he was a true believer, a justified person, approved of God, and loved by him. Now if this was the case of Abraham, the father of the Jewish nation, yea, the father of the faithful, of all that believe, he is, and must be a vain man, that talks of faith without works; and his faith must be a dead one, and he be very unlike the father of them that believe: the good work instanced in is the offering up of Isaac;
when he had offered Isaac his son upon the altar:
for when he was bid to take his son, his only and beloved son, Isaac, and offer him up on one of the mountains, that should be shown him, he made haste to do it; he provided everything for it; he split the wood, and carried it with him, and fire in his hand; he built an altar, laid the wood on it, bound his son, laid the wood on the altar, and his son on the wood, and stretched out his hand, with his knife in it, to slay him; so that it was all one, with respect to his intention and will, as if he had actually offered him, and was a full trial and proof of his obedience to God. This was not the only act of obedience, or good work, which he performed; but this being a very eminent one, the apostle instances in it, as a very considerable evidence of his faith in God, and love to him; and which showed him to be a justified person, as he was long before he performed this action, even before Isaac was born; see ( Genesis 15:6 ) and therefore it can never be the apostle's meaning, that he was justified before God by this, or any other good work or works, as cause or causes of it; but only that he was declared to be so; or, in other words, that his faith was attended with good works, and evidenced by them.