Matthew 16:6

Leaven of the Pharisees. See on eh. 13:33. Here “leaven” refers specifically to the “doctrine” of the Pharisees and the Sadducees (see eh. 16:12), that is, to their principles and teachings. As leaven permeates a lump of dough, so the principles a man accepts permeate his life. The comparison is apt indeed, whether the principles be good or evil. The spirit, teachings, and character of the religious leaders, revealed in their hypocrisy, pride, ostentation, and formalism, would inevitably affect the lives of those who esteemed them and complied with their instructions. In this particular instance Jesus referred to the spirit of the Pharisees and Sadducees (cf. Mark 8:15) that led them to ask for a sign. Later Jesus compared their hypocrisy to leaven (see Luke 12:1; cf. Matt. 23:2, 3).