By St. Cyril of Alexandria
(Excerpts from Sermon 29 on the Gospel of Luke)
6:31. As ye wish that men should do unto you, even so do ye unto them.
It was probable however that the holy apostles would perchance think these things difficult to put into practice: He therefore Who knows all things takes the natural law of self-love as the arbiter of what any one would wish to obtain from another. Show yourselfself, He says, to others such as you wish them to be towards you. If you would have them be harsh and unfeeling, fierce and wrathful, revengeful and ill-disposed, show yourself also such, but if on the contrary you would have them be kind and forgiving, do not think it a thing intolerable to be yourself so. And in the case of those so disposed, the law is perchance unnecessary, because God writes upon our hearts the knowledge of His will: "for in those days, saith the Lord, I will surely give My laws into their mind, and will write them on their heart."
6:36. Be ye therefore merciful.
Great is the glory of compassion, and so verily it is written, that "man is a great thing, and the merciful man an honorable thing." For virtue restores us to the likeness of God, and imprints on our souls certain characters as it were of the supreme nature.