Matthew 16:1-3

The Pharisees and Sadducees came up, and putting Jesus to the test, they asked Him to show them a sign from heaven.

But He replied to them, “When it is evening, you say, ‘It will be fair weather, for the sky is red.’

And in the morning, ‘There will be a storm today, for the sky is red and threatening.’ You know how to discern the appearance of the sky, but are you unable to discern the signs of the times?