Jerome
Catena Aurea · Matthäusevangelium 16
And when his disciples were come to the other side, they had forgotten to take bread. Then Jesus said unto them, Take heed and beware of the leaven of the Pharisees and of the Sadducees. And they reasoned among themselves, saying, It is because we have taken no bread. Which when Jesus perceived, he said unto them, O ye of little faith, why reason ye among yourselves, because ye have brought no bread? Do ye not yet understand, neither remember the five loaves of the five thousand, and how many baskets ye took up? Neither the seven loaves of the four thousand, and how many baskets ye took up? How is it that ye do not understand that I spake it not to you concerning bread, that ye should beware of the leaven of the Pharisees and of the Sadducees? Then understood they how that he bade them not beware of the leaven of bread, but of the doctrine of the Pharisees and of the Sadducees.
Thus He takes this occasion to instruct them what is meant by the five loaves and the seven loaves, the five thousand and the four thousand, who were fed in the desert. For if the leaven of the Pharisees and Sadducees signified not earthly food, but corrupt traditions and heretical dogmas, why should not the food with which the people of God is nourished signify the true and uncorrupt doctrine?