Tertullian

“ After that, the Lord, “amplifying the Law,” [9] openly adds the prohibition of anger against a brother to that of murder. [10] Not even by an evil word does He permit it to be vented. [11] Ever if we must be angry, our anger must not be maintained beyond sunset, as the apostle admonishes. [12] But how rash is it either to pass a day without prayer, while you refuse to make satisfaction to your brother ”