"For let not the sun," says he, "go down upon your wrath."
Would you have your fill of anger? One hour, or two, or three, is enough for you; let not the sun depart, and leave you both at enmity. It was of God's goodness that he rose: let him not depart, having shone on unworthy men. For if the Lord of His great goodness sent him, and has Himself forgiven you your sins, and yet you forgive not your neighbor, look, how great an evil is this!
And there is yet another besides this. The blessed Paul dreads the night, lest overtaking in solitude him that was wronged, still burning with anger, it should again kindle up the fire. For as long as there are many things in the daytime to banish it, you are free to indulge it; but as soon as ever the evening comes on, be reconciled, extinguish the evil while it is yet fresh; for should night overtake it, the morrow will not avail to extinguish the further evil which will have been collected in the night.
Nay, even though you should cut off the greater portion, and yet not be able to cut off the whole, it will again supply from what is left for the following night, to make the blaze more violent. And just as, should the sun be unable by the heat of the day to soften and disperse that part of the air which has been during the night condensed into cloud, it affords material for a tempest, night overtaking the remainder, and feeding it again with fresh vapors: so also is it in the case of anger.
- John Chrysostom, Ephesians, homily 14