Here the apostle digresseth a little from his principal argument, and falls into a commendation of Abraham's faith. Who against hope believed in hope: Abraham, when he had no natural or rational grounds of hope, either in respect of himself or Sarah his wife, did yet believe and hope he should have a son; and so be a root or stock, from whence many nations should spring: and this faith and hope of his was grounded upon the power and faithfulness of God. So shall thy seed be; so as the stars of heaven for multitude, which must be supplied out of the promise, in Genesis 15:5.
Related Commentaries of Romans 4:18
Romans 4:18
18 Who against hope believed in hope, that he might become the father of many nations, according to that which was spoken, So shall thy seed be.