Matthew 16:1-12 NLT
One day the Pharisees and Sadducees came to test Jesus, demanding that he show them a miraculous sign from heaven to prove his authority.
He replied, “You know the saying, ‘Red sky at night means fair weather tomorrow; red sky in the morning means foul weather all day.’ You know how to interpret the weather signs in the sky, but you don’t know how to interpret the signs of the times! Only an evil, adulterous generation would demand a miraculous sign, but the only sign I will give them is the sign of the prophet Jonah.” Then Jesus left them and went away.
Later, after they crossed to the other side of the lake, the disciples discovered they had forgotten to bring any bread. “Watch out!” Jesus warned them. “Beware of the yeast of the Pharisees and Sadducees.”
At this they began to argue with each other because they hadn’t brought any bread. Jesus knew what they were saying, so he said, “You have so little faith! Why are you arguing with each other about having no bread? Don’t you understand even yet? Don’t you remember the 5,000 I fed with five loaves, and the baskets of leftovers you picked up? Or the 4,000 I fed with seven loaves, and the large baskets of leftovers you picked up? Why can’t you understand that I’m not talking about bread? So again I say, ‘Beware of the yeast of the Pharisees and Sadducees.’”
Then at last they understood that he wasn’t speaking about the yeast in bread, but about the deceptive teaching of the Pharisees and Sadducees.
NLT: New Living Translation