Sahl ibn Sa'd related that the name which 'Ali, may Allah be pleased with him, liked best was Abu Turab and that he was happy when he was called that. Only the Prophet (ﷺ) called him that. One day 'Ali was cross with Fatima and went out and reclined against the wall of the mosque. The Prophet (ﷺ) came to look for him and was told that he was leaning against the wall. The Prophet (ﷺ) went up to him and found that his back was covered with dust. The Prophet (ﷺ) began to wipe the dust off his back and said, 'Sit down Abu Turab (father of dust)!'"