Sunan Ibn Majah, Volume 5, Book 37, Hadith 4184 (DarusSalam) ⓘ
It was narrated from Abu Bakrah that the Messenger of Allah said: “Modesty is part of faith, and faith will be in Paradise. Obscenity in speech is part of harshness and harshness will be in Hell.’”
حَدَّثَنَا إِسْمَاعِيلُ بْنُ مُوسَى، حَدَّثَنَا هُشَيْمٌ، عَنْ مَنْصُورٍ، عَنِ الْحَسَنِ، عَنْ أَبِي بَكْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " الْحَيَاءُ مِنَ الإِيمَانِ وَالإِيمَانُ فِي الْجَنَّةِ وَالْبَذَاءُ مِنَ الْجَفَاءِ وَالْجَفَاءُ فِي النَّارِ " .
also referenced under: Hadith 4184 (Reference) & Book 37, Hadith 4324 (In-Book)