When we're looking for a sign for God to prove himself, we might be wise to remember this passage. Jesus had peformed miracles in the cities and towns around him, but the miracles weren't the point. They were supposed to be signposts pointing to something greater, a Kingdom that was breaking through. To receive such direct proof of its existence and still turn away brought rebuke from Jesus. Often he commended those who believed without seeing, and certainly he had harsh words for those who saw and yet refused to be obedient.