John Chrysostom

The teacher ought to do nothing with a feeling of being burdened, that tends to the salvation of his disciples. For if the blessed Jacob was buffeted night and day in keeping his flocks, much more ought he, to whom the care of souls is entrusted, to endure all toils, though the work be laborious and mean, looking only to one thing, the salvation of his disciples, and the glory thence arising to God. …

Homily on 1 Thessalonians 3 ↗

Theophylact of Ohrid

He did not say: remember our benefactions, but "labor," and not simply that, but also "toil," that is, labor with great diligence. And not only during the day, but also at night. Such is the zeal and such is the care — so as not to cause anyone to stumble! With the words "so as not to burden any of you," he shows that the Thessalonians were in poverty.

Commentary on 1 Thessalonians ↗

Thomas Aquinas

Then when Paul says: for you remember our labor and toil, brethren, he proceeds in accordance with what he had said above, that is: we never used a cloak for greed, for we have asked nothing of you, but an effort, for you remember our labor and toil. And some do indeed labor, but out of comfort seeking; but we do not labor in that manner, but rather with honest hard work. So Paul comments: our labor, not merely for the sake of discipline of the body, but with genuine toil. Therefore Paul adds, you remember our toil. …

Commentary on 1 Thessalonians ↗

Caesarius of Arles

Perhaps someone says: Who can always be thinking of God and eternal bliss, since all men must be concerned for food, clothing and the management of their household? God does not bid us be free from all anxiety over the present life, for he instructs us through his apostle: "If any man will not work, neither let him eat." The same apostle repeats the idea with reference to himself when he says: "We worked night and day so that we might not burden any of you." Since God especially advises reasonable thought of food and clothing, so …

Homilies Concerning the Statues 2.8