Then Jesus said unto them
Either taking occasion from the disciples observing that they had forgot to take bread with them, or on account of what passed between him and the Pharisees and Sadducees, he gave the following advice to his disciples;
take heed and beware of the leaven of the Pharisees and of the
Mark, instead "of the leaven of the Sadducees", says, "the leaven of Herod"; either because Christ might caution against all three; or because the Sadducees were generally Herodians, taking Herod to be the Messiah; or were on his party, or for his government, which the Pharisees disliked; and the Herodians were generally Sadducees. By "the leaven" of these is meant their doctrine, as appears from ( Matthew 16:12 ) . The doctrines the Pharisees taught were the commandments and inventions of men, the traditions of the elders, free will, and justification by the works of the law: the doctrine of the Sadducees was, that there was no resurrection of the dead, nor angels, nor spirits: now because they sought secretly and artfully to infuse their notions into the minds of men; and which, when imbibed, spread their infection, and made men sour, morose, rigid, and ill natured, and swelled and puffed them up with pride and vanity, Christ compares them to leaven; and advises his disciples to look about them, to watch, and be on their guard, lest they should be infected with them.