Leaven is a representation used to describe a product of the Pharisees, Sadducees and Herod.
What was it about the Pharisees, Sadducees and Herod, or the Herodian’s, that Jesus wanted his followers to beware of?
The Pharisees, Sadducees and Herodians had an appearance of virtue veiled in religion and government wrapped in hypocrisy, unbelief, and worldliness.