John Calvin Commentary 1 Thessalonians 5:27

"I adjure you by the Lord that this epistle be read unto all the brethren." — 1 Thessalonians 5:27 (ASV)

I adjure you by the Lord. It is not certain whether he feared that, as often happened, spiteful and envious persons would suppress the Epistle, or whether he wished to guard against another danger — lest, through a mistaken prudence and caution on the part of some, it might be kept among a few.

For there will always be some who say that it is of no advantage to publish widely things that they otherwise recognize as very excellent. At least, whatever artifice or pretext Satan may have contrived at that time, so that the Epistle might not become known to all, we may gather from Paul’s words with what earnestness and keenness he sets himself in opposition to it.

For it is no light or frivolous thing to adjure by the name of God. We find, therefore, that the Spirit of God intended that those things which he had set forth in this Epistle, through the ministry of Paul, should be published throughout the whole Church. Hence it appears that those who today prohibit the people of God from reading the writings of Paul are more refractory than even devils themselves, since they are in no way moved by such a strict adjuration.