Al-Kāfi

Hadith 1164
evil-behaviorbackbiting-slander
4ـ عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ سَهْلِ بْنِ زِيَادٍ عَنْ صَفْوَانَ عَنْ عِيصِ بْنِ الْقَاسِمِ عَنْ أَبِي عَبْدِ الله (عَلَيهِ السَّلام) قَالَ إِنَّ أَبْغَضَ خَلْقِ الله عَبْدٌ اتَّقَى النَّاسُ لِسَانَهُ.
4. A number of our people have narrated from Sahl ibn Ziyad from Safwan from ‘Iys ibn al-Qasim from Abu ‘Abdillah (a.s.) who has said the following: “Abu ‘Abd Allah (a.s.) has said, ‘The most hated of the creatures of Allah is one from whose tongue people are afraid.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī