John Calvin Commentary 1 Thessalonians 4:6

"that no man transgress, and wrong his brother in the matter: because the Lord is an avenger in all these things, as also we forewarned you and testified." — 1 Thessalonians 4:6 (ASV)

Let no man oppress. Here we have another exhortation, which flows, like a stream, from the doctrine of sanctification. “God,” says he, “has it in view to sanctify us, that no man may do injury to his brother.” As for Chrysostom’s connecting this statement with the preceding one, and explaining ὑπερβαίνειν καὶ πλεονεκτεῖν to mean—neighing after the wives of others (Jeremiah 5:8), and eagerly desiring them—this is too forced an exposition.

Paul, accordingly, having cited one instance of unchastity regarding lasciviousness and lust, teaches that this also is a department of holiness—that we conduct ourselves righteously and harmlessly towards our neighbors. The former verb refers to violent oppressions—where the man who has more power emboldens himself to inflict injury.

The latter includes all immoderate and unrighteous desires. However, since mankind, for the most part, indulges in lust and avarice, he reminds them of what he had formerly taught—that God would be the avenger of all such things. We must observe, however, what he says—we have solemnly testified; for such is the sluggishness of mankind that, unless they are wounded to the quick, they are not stirred by any apprehension of God’s judgment.