Matthew 16:1-4

1 And the Pharisees and Sadducees came and, testing him, made a request to him to give them a sign from heaven.

2 But in answer he said to them, At nightfall you say, The weather will be good, for the sky is red.

3 And in the morning, The weather will be bad today, for the sky is red and angry. You are able to see the face of heaven, but not the signs of the times.

4 An evil and false generation is searching after a sign; and no sign will be given to it but the sign of Jonah. And he went away from them.