Augustine of Hippo
Catena Aurea · Matthäusevangelium 18
Moreover if thy brother shall trespass against thee, go and tell him his fault between thee and him alone: if he shall hear thee, thou hast gained thy brother. But if he will not hear thee, then take with thee one or two more, that in the mouth of two or three witnesses every word may be established. And if he shall neglect to hear them, tell it unto the Church: but if he neglect to hear the Church, let him be unto thee as an heathen man and a Publican.
(Serm. 82. 1.) Our Lord admonishes us not to overlook one another’s faults, yet not so as seeking for matter of blame, but watching what you may amend. For our rebuke should be in love, not eager to wound, but anxious to amend. If you pass it by, you are become worse than he. He by doing you a wrong hath done himself a great hurt; you slight your brother’s wound, and are more to blame for your silence than he for his ill words to you.