3 We have therefore to give those who are disturbed by this the answer, that they were not prohibited from seeking necessary sustenance by their manual craft, when lawful in itself, and warranted so long as they preserved their apostleship intact, if at any time they had no other means of gaining a livelihood. Unless any one have the boldness to imagine or to affirm, that the Apostle Paul attained not to the perfection of those who left all and followed Christ, seeing that, in order not to become a burden to any of those to whom he preached the gospel, he worked with his own hands for his support: wherein we find rather the fulfillment of his own words, “I labored more abundantly than they all;” and to which he added, “yet not I, but the grace of God that was with me:” to make it manifest that this also was to be imputed to the grace of God, that both with mind and body he was able to labor so much more abundantly than they all, that he neither ceased from preaching the gospel, nor drew, like them, his present support out of the gospel; while he was sowing it much more widely and fruitfully through multitudes of nations where the name of Christ had never previously been proclaimed. Whereby he showed that living, that is, deriving their subsistence, by the gospel, was not imposed on the apostles as a necessity, but conferred on them as a power. And of this power the same apostle makes mention when he says: “If we have sown to you spiritual things, is it a great thing if we reap your carnal things? If others are partakers of this power among you, are not we rather? But,” he adds, “we have not used this power.” And a little afterwards he says: “They who serve the altar are partakers with the altar: even so has the Lord ordained, that they who preach the gospel should live of the gospel; but I have used none of these things.” It is clear enough, therefore, that it was not enjoined on the apostles, but put in their power, not to find their living otherwise than by the gospel, and of those to whom by preaching the gospel they sowed spiritual things, to reap their carnal things; that is, to take their bodily support, and, as the soldiers of Christ, to receive the wages due to them, as from the inhabitants of provinces subject to Christ. Hence that same illustrious soldier had said a little before, in reference to this matter, “Who goes a warfare any time at his own charges?” Which he nevertheless did himself; for he labored more abundantly than they all. If, then, the blessed Paul— that he might not use with them the power which he certainly possessed along with the other preachers of the gospel, but went a warfare at his own charges, that the Gentiles, who were utterly averse to the name of Christ, might not take offense at his teaching, as something offered them for a money equivalent—in a way very different from that in which he had been educated, learned an altogether new art, that while the teacher supports himself with his own hands, none of his hearers might be burdened; how much rather did the blessed Peter, who had beforetimes been a fisherman, do what he was already acquainted with, if at that present time he found no other means of gaining a livelihood?
Source: Tractates on the Gospel of John (New Advent)