The Messenger of Allah ﷺ said, "Modesty is part of faith, and faith leads to Paradise. Foul speech is part of harshness, and harshness leads to the Fire."
قال رسول الله ﷺ: الحياء من الإيمان، والإيمان في الجنة، والبذاء من الجفاء، والجفاء في النار.
Tirmidhi (2009) and Ahmad (10512) narrated it, and Ibn Hibban (608) and Hakim (5352/1) both graded it sahih, all of them via the route of Muhammad bin Amr, from Abu Salama, from Abu Hurairah, who related it.Its chain is hasan because of Muhammad bin Amr, who is Al-Laythi, for his hadith are graded hasan.Tirmidhi said, "This is a hasan sahih hadith."