Matthew 16:1-4 New American Standard Bible (NASB)
16 The Pharisees and Sadducees came up, and testing Jesus, they asked Him to show them a sign from heaven. 2 But He replied to them, “When it is evening, you say, ‘It will be fair weather, for the sky is red.’3 And in the morning, ‘There will be a storm today, for the sky is red and threatening.’ Do you know how to discern the appearance of the sky, but cannot discern the signs of the times? 4 An evil and adulterous generation seeks after a sign; and a sign will not be given it, except the sign of Jonah.” And He left them and went away.