John Cassian, The Institutes X.9: That not the Apostle only, but those two who were with him laboured with their own hands

And he testifies that it was not he alone who so lived among them, lest haply this method might not seem important or general if he depended only on his example. But he declares that all those who were appointed with him for the ministry of the gospel, i.e., Silvanus and Timothy, who wrote this with him, worked in the same fashion. For by saying, “lest we should be burdensome to any of you, he covers them with great shame. For if he who preached the gospel and commended it by signs and mighty works, did not dare to eat bread for nought, lest he should be burdensome to any, how can those men help thinking that they are burdensome who take it every day in idleness and at their leisure?