Augustine of Hippo — as excerpted in the Catena Aurea on Matthew 5:38-42

“(Serm. in Mont. i. 19.) The third kind of wrongs, which is in the matter of labour, consists of both such as admit restitution, and such as do not—or with or without revenge—for he who forcibly presses a man’s service, and makes him give him aid against his will, can either be punished for his crime, or return the labour. In this kind of wrongs then, the Lord teaches that the Christian mind is most patient, and prepared to endure yet more than is offered; If a man constrain thee to go with him a mile, go with him yet other two. This likewise is meant not so much of actual service with your feet, as of readiness of mind.”