Ephesians 4:26

Be ye angry, and sin not: let not the sun go down upon your wrath:

Ver. 26. Be angry and sin not] The easiest charge under the hardest condition that can be. Anger is a tender virtue, and must be warily managed. He that will be angry and not sin, let him be angry at nothing but sin.

Let not the sun go down] If ye have overshot in passion, let it not rest or roost in you, lest it become malice. Plutarch writeth that it was the custom of Pythagoras' scholars, however they had been at odds, jarring and jangling in their disputations, yet before the sun set to kiss and shake hands as they departed out of the school. a How many are there that professing themselves the scholars of Christ, do yet nevertheless not only let the sun go down, but go round his whole course, and can find no time from one end of the year to the other to compose and lay aside their discords! How should this fire be raked up when the curfew bell rings! William the Conqueror commanded that cover-few (curfew) bell. It were well that some were admonished every night to cover the fire of their passions, that their wrath might not be memor ira, unforgetable wrath, as Virgil hath it, and αειμνηστος, as that of the Athenians, who hated all barbarians, for the Persians' sake, and forbade them their sacrifices, as they used to do murderers. (Rous's Arch. Attic.) Leontius Patritius was one day extremely and unreasonably angry with John, Patriarch of Alexandria: at evening, the patriarch sent a servant to him with this message; "Sir, the sun is set;" upon which Patritius reflecting, and the grace of God making the impression deep, he threw away his anger, and became wholly subject to the counsel of the patriarch. (Taylor's Life and Death of Christ.)

a Plut. lib. περι φιλαδελφ .