'Leaven of the Pharisees' in the Bible

And Jesus said to them, "Take heed, and beware of the leaven of the Pharisees and Sadducees."

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

And He was charging them, saying, "Take heed, beware of the leaven of the Pharisees, and of the leaven of Herod."

In the meantime, the vast multitude having been gathered together, so as to tread one upon another, He began to say to His disciples, first, "Beware of the leaven of the Pharisees, which is hypocrisy.