[In the following commentary, some preceding verses have been included, because Bl. Theophylact comments on them as a whole.]
27-36. But I say unto you which hear, Love your enemies, do good to them which hate you, bless them that curse you, and pray for them which despitefully use you. And unto him that smiteth thee on the one cheek offer also the other; and him that taketh away thy cloak forbid not to take thy tunic also. Give to every man that asketh of thee; and of him that taketh away thy goods ask them not again. And as ye would that men should do to you, do ye also to them likewise. For if ye love them which love you, what thank have ye? For sinners also love those that love them. And if ye do good to them which do good to you, what thank have ye? For sinners also do even the same. And if ye lend to them of whom ye hope to receive, what thank have ye? For sinners also lend to sinners, to receive as much again. But love ye your enemies, and do good, and lend, hoping for nothing again; and your reward shall be great, and ye shall be the sons of the Most High; for He is kind unto the unthankful and to the evil. Be ye therefore merciful, as your Father also is merciful. The Apostles were about to be sent out to preach and many persecutors and plotters awaited them. If the Apostles were fearful and dismayed by persecution, they might want to protect themselves from their persecutors by keeping silent and not teaching. If that happened, the radiant sun of the Gospel would be extinguished. In anticipation of this, the Lord exhorts the Apostles not to give way to defensive measures against their enemies, but instead bravely to endure all things, even insults and murderous plots. This is what He Himself did on the Cross, saying, Father, forgive them, for they know not what they do (Lk.23:34). To prove to the Apostles that this commandment to love ones enemies is possible to keep, He then says, "What you want to be done to you, do the same to others; and be to others that kind of person you want others to be to you." If you want your enemies to be hard, unfeeling, and angry towards you, then be the same yourself to them. But if you want them to be kind and compassionate towards you, and not to remember wrongs, do not think that it is impossible for you yourself to be the same towards them. Do you see this natural law which is written in our hearts? That is why the Lord also said, In those days I will surely put My laws into their mind, and write them on their hearts (Jer. 38:33). Then He adds another compelling reason to keep this commandment: if you love those who love you, you are like the sinners and the Gentiles; but if you love those who do evil to you, you are like God, Who is kind unto the unthankful and to the evil. Which do you desire—to be like sinners or to be like God? Do you see the divine teaching? First He persuaded you by means of the natural law: what you want to be done to you, do to others. Then He persuades you with the result and the reward—He promises that you will become like God.