Matthew 16:5-6, 11-12

Later, as Jesus and his disciples crossed over to the other side of Lake Galilee, the disciples realized they had forgotten to bring any loaves of bread. Jesus spoke up and said, “Watch out for the yeast of the Pharisees and the Sadducees.”

Don’t you understand? I’m not talking about bread, but I’m warning you to avoid the yeast of the Pharisees and the Sadducees.” Then finally they realized he wasn’t talking about yeast found in bread, but the error of the teachings of the Pharisees and the Sadducees.