The Messenger of Allah ﷺ said, "The believer is not one who slanders, nor one who curses, nor one who is obscene and vulgar."Ibn Sabiq once narrated it as, "neither a slanderer nor a curser."
حدثنا محمد بن سابق حدثنا إسرائيل عن الأعمش عن إبراهيم عن علقمة
قال رسول الله ﷺ ليس المؤمن بطعان ولا بلعان ولا الفاحش البذيء وقال ابن سابق مرة بالطعان ولا باللعان
Its isnad is sahih. Tirmidhi related it (3:138) from Muhammad bin Yahya Azdi, from Muhammad bin Sabiq, and said, "A hasan gharib hadith, and it has been related from Abdullah by a route other than this one."Its commentator also attributed it to Bukhari in his Tarikh, Ibn Hibban in his Sahih, Hakim in his Mustadrak, and Bayhaqi in Shuab al-Iman.In one copy, in the margin of K, the wording is, "nor foul-mouthed nor obscene," which agrees with Tirmidhi's version.