Matthew 16:9 (KJV)

A wicked and adulterous generation seeketh after a sign; and there shall no sign be given unto it, but the sign of the prophet Jonas. And he left them, and departed.

And when his disciples were come to the other side, they had forgotten to take bread.

Then Jesus said unto them, Take heed and beware of the leaven of the Pharisees and of the Sadducees.

And they reasoned among themselves, saying, It is because we have taken no bread.

Which when Jesus perceived, he said unto them, O ye of little faith, why reason ye among yourselves, because ye have brought no bread?

Neither the seven loaves of the four thousand, and how many baskets ye took up?

How is it that ye do not understand that I spake it not to you concerning bread, that ye should beware of the leaven of the Pharisees and of the Sadducees?

Then understood they how that he bade them not beware of the leaven of bread, but of the doctrine of the Pharisees and of the Sadducees.

When Jesus came into the coasts of Caesarea Philippi, he asked his disciples, saying, Whom do men say that I the Son of man am?

And they said, Some say that thou art John the Baptist: some, Elias; and others, Jeremias, or one of the prophets.