Then they perceived that He had not warned them against bread-yeast, but against the teaching of the Pharisees and Sadducees.

Therefore let us keep our festival not with old yeast nor with the yeast of what is evil and mischievous, but with bread free from yeast--the bread of transparent sincerity and of truth.

How is it you do not understand that it was not about bread that I spoke to you? But beware of the yeast of the Pharisees and Sadducees."