Treasury of Scripture Knowledge
2 Thessalonians 2:2
not to be quickly shaken in your mind, nor yet be troubled, either by spirit, or by word, or by letter as from us, saying that the day of Christ had come.
2 Thessalonians 3:14
If any man doesn't obey our word in this letter, note that man, that you have no company with him, to the end that he may be ashamed.