Luke 6:32-34 FNV
There are three manners of return, as Augustine - quoted by Archbishop Trench in his 'Exposition of the Sermon on the Mount' - observes, which men may make one to another: the returning good for good and evil for evil, - this is the ordinary rule of man; then beneath this there is the returning of evil for good, which is devilish; while above it there is the returning of good for evil, which is Divine, - and this is what is commanded for the followers of Jesus here.
The strength of our Saviour’s argument lieth in this, That God expects that those who have received more grace and favour from God than others, and who make a higher profession than others, should do more in obedience to the positive commands of God, and the revelations of his will in his word, than they who live merely by the light of nature, and live up merely to the law of nature.
[Excerpt from The Pulpit Commentary & Matthew Poole's Commentary]