33 The kingdom of heaven is like to leaven, which a woman took and hid in three measures of meal, until the whole was leavened.
Chrysostom: Leaven is kneaded in, without being destroyed, but gradually changes all things into its own nature; so shall it come to pass with [His disciples’] preaching.
He says, “three measures,” to signify a great abundance.
Augustine: The leaven signifies love, because it causes activity and fermentation; by the woman He means wisdom. By the three measures He intends either those three things in man, with the whole heart, with the whole soul, with the whole mind; or the three degrees of fruitfulness, the hundred-fold, the sixty-fold, the thirty-fold [Matt 13:8]; or those three kinds of men, Noe, Daniel, and Job.
Rabanus: He says, “Until the whole was leavened,” because that love implanted in our mind ought to grow until it changes the whole soul into its own perfection; which is begun here, but is completed hereafter.
Jerome: The woman who takes the leaven and hides it, seems to me to be the Apostolic preaching, or the Church gathered out of divers nations. She takes the leaven, that is, the understanding of the Scriptures, and hides it in three measures of meal, that the three, spirit, soul, and body, may be brought into one, and may not differ among themselves.
We read in Plato that there are three parts in the soul, reason, anger, and desire; so we also if we have received the evangelic leaven of Holy Scripture, may possess in our reason prudence, in our anger hatred against vice, in our desire love of the virtues, and this will all come to pass by the Evangelic teaching which our mother Church has held out to us.
I will further mention an interpretation of some; that the woman is the Church, who has mingled the faith of man in three measures of meal, namely, belief in the Father, the Son, and the Holy Spirit; which when it has fermented into one lump, brings us not to a threefold God, but to the knowledge of one Divinity.
Hilary: The Lord compares Himself to leaven; for leaven is produced from meal, and communicates the power that it has received to a heap of its own kind.
Scripture from the Douay-Rheims Bible. Commentary from St. Thomas Aquinas, Catena Aurea, Vol. I (London: Rivington, 1842).