Then he said unto them, O fools, and slow of heart to believe all that the prophets have spoken: O fools and slow of heart to believe - Inconsiderate men, justly termed such, because they had not properly attended to the description given of the Messiah by the prophets, nor to his teaching and miracles, as proofs that He alone was the person they described.
Slow of heart - Backward, not easy to be persuaded of the truth, always giving way to doubtfulness and distrust. This very imperfection in them is a strong evidence of the truth of the doctrine which they afterwards believed, and proclaimed to the world. Had they not had the fullest assurance of these things, they never would have credited them; and it is no small honor to the new-covenant Scriptures that such persons were chosen, first, to believe them; secondly, to proclaim them in the world; and, thirdly, to die on the evidence of those truths, the blessed influence of which they felt in their own hearts, and fully exemplified in their lives.