Catena Aurea, Matthew 22:34-40, 30th Sunday in Ordinary time, Year A.
St. Jerome (340/2-420): The Pharisees having been themselves already confuted (in the matter of the denarius), and now seeing their adversaries also overthrown, should have taken warning to attempt no further deceit against Him; but hate and jealousy are the parents of imprudence.
St. Augustine (354-430) You are commanded to love God “with all your heart,” that is, your whole thoughts— “with all your soul,” that is, your whole life— “with all your mind,” that is, your whole understanding— so that these may be given to Him from whom you have received them, so that you may give them. Thus He has left no part of our life which may justly be un-filled with Him; but if anything else presents itself for the soul’s love, it should be absorbed into that channel in which the whole current of love runs. For man is then the most perfect when his whole life tends towards the life which is unchangeable, and clings to it with the whole purpose of his soul.
Pseudo-Chrysostom: But whoever loves man is like someone who loves God; for man is God’s image, wherein God is loved, as a King is honoured in his statue. For this reason this commandment is said to be like the first.
St. Hilary of Poitiers (300-368): Or otherwise; That the second command is like [p. 764] the first signifies that the obligation and merit of both are alike; for no love of God without Christ, or of Christ without God, can profit to salvation. It follows, “On these two commandments hang all the Law and the Prophets.”
Rabanus Maurus (c. 780-856): For to these two commandments belongs the whole Ten Commandments; the first three commandments to the love of God, and the remaining seven to the love of our neighbour.