He looked upon God as one that was perfectly able to do whatever he had promised, and as one that was most faithful, and sure never to fail in the performance; collecting nothing else from the difficulty and improbability of the matter, but that it was the fitter for an Almighty power to effect.
Related Commentaries of Romans 4:21
Romans 4:21
21 And being fully persuaded that, what he had promised, he was able also to perform.