3 and in the morning, ‘Today it will be stormy, for the sky is red and overcast.’ You know how to interpret the appearance of the sky, but you cannot interpret the signs of the times.a
4 A wicked and adulterous generation looks for a sign, but none will be given it except the sign of Jonah.” Jesus then left them and went away.

The Yeast of the Pharisees and Sadducees

5 When they went across the lake, the disciples forgot to take bread.
6 “Be careful,” Jesus said to them. “Be on your guard against the yeast of the Pharisees and Sadducees.”
7 They discussed this among themselves and said, “It is because we didn’t bring any bread.”