John Chrysostom
Catena Aurea · Lukasevangelium 10
And, behold, a certain Lawyer stood up, and tempted him, saying, Master, what shall I do to inherit eternal life? He said unto him, What is written in the law? how readest thou? And he answering said, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy strength, and with all thy mind; and thy neighbour as thyself. And he said unto him, Thou hast answered right: this do, and thou shalt live.
(Hom. 32. in 1 Cor.) Yet observe how, almost to the same extent of obedience he requires the performance of each command, For of God he says, with all thy heart. Of our neighbour, as thyself. Which if it were diligently kept, there would be neither slave nor free man, neither conqueror nor conquered, (or rather, neither prince nor subject,) rich nor poor, nor would the devil be even known, for the chaff would rather stand the touch of fire than the devil the fervour of love; so surpassing all things is the constancy of love.