(113) باب التَّكَنِّي بِأَبِي تُرَابٍ، وَإِنْ كَانَتْ لَهُ كُنْيَةٌ أُخْرَى
Narrated Sahl bin Sa`d:
The most beloved names to `Ali was Abu Turab, and he used to be pleased when we called him by it, for none named him Abu Turab (for the first time), but the Prophet. Once `Ali got angry with (his wife) Fatima, and went out (of his house) and slept near a wall in the mosque. The Prophet (ﷺ) came searching for him, and someone said, "He is there, Lying near the wall." The Prophet (ﷺ) came to him while his (`Ali's) back was covered with dust. The Prophet (ﷺ) started removing the dust from his back, saying, "Get up, O Abu Turab!"
Reference: Sahih al-Bukhari 6204
In-book reference: Book 78, Hadith 228
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 73, Hadith 223