John Cassian, The Institutes X.11: That he preached and taught men to work not only by his example, but also by his words

But lest haply it might be thought that, while he worked in silence and tried to teach them by example, he had not instructed them by precepts and warnings, he proceeds to say: “For when we were with you, this we declared to you, that if a man will not work neither should he eat.” Still greater does he make their idleness appear, for, though they knew that he, like a good master, worked with his hands for the sake of his teaching and in order to instruct them, yet they were ashamed to imitate him; and he emphasizes our diligence and care by saying that he did not only give them this for an example when present, but that he also proclaimed it continually in words; saying that if any one would not work, neither should he eat.