'Epistle' in the Bible

to the end that ye be not quickly shaken from your mind, nor yet be troubled, either by spirit, or by word, or by epistle as from us, as that the day of the Lord is just at hand;

Therefore, brethren, stand fast, and hold the traditions which ye have been taught, whether by word, or our epistle.

And if any man obey not our word by this epistle, note that man, and have no company with him, that he may be ashamed.

The salutation of Paul with mine own hand, which is the token in every epistle: so I write.