The Pharisees also with the Sadducees came, and testing him desired that he would show them a sign from heaven. He answered and said unto them, When it is evening, you say, It will be fair weather: for the sky is red. And in the morning, It will be foul weather today: for the sky is red and overcast. O you hypocrites, you can discern the appearance of the sky; but can you not discern the signs of the times? A wicked and adulterous generation seeks after a sign; and there shall no sign be given unto it, but the sign of the prophet Jonah. And he left them, and departed. (Matthew 16:1-4)