Sahih Bukhari | Volume 8 | Hadith Number 223
Narrated by Sahl bin Sad
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 came searching for him, and someone said, "He is there, Lying near the wall." The Prophet came to him while his ('Ali's) back was covered with dust. The Prophet started removing the dust from his back, saying, "Get up, O Abu Turab!"