Matthew 16:1, 6, 12

The Pharisees also with the Sadducees came, and tempting desired him that he would shew them a sign from heaven.

Then Jesus said unto them, Take heed and 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.