Matthew 16:6 - Clarke's commentary and critical notes on the Bible

Then Jesus said unto them, Take heed and beware of the leaven of the Pharisees and of the Sadducees. Beware of the leaven - What the leaven of Pharisees and Sadducees was has been already explained, see Matthew 16:1. Bad doctrines act in the soul as leaven does in meal; they assimulate the whole Spirit to their own nature. A man's particular creed has a greater influence on his tempers and conduct than most are aware of. Pride, hypocrisy, and worldly-mindedness, which constituted the leaven of the Pharisees and Sadducees, ruin the major part of the world.