'Leaven of the Pharisees' in the Bible

And Jesus said unto 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 charged them, saying, Take heed, beware of the leaven of the Pharisees and the leaven of Herod.

In the mean time, when the many thousands of the multitude were gathered together, insomuch that they trod one upon another, he began to say unto his disciples first of all, Beware ye of the leaven of the Pharisees, which is hypocrisy.