عَنْ عَمَّارِ بْنِ يَاسِرٍ رَضِيَ اللَّهُ عَنْهُ قَالَ كُنْتُ أَنَا وَعَلِيٌّ رَفِيقَيْنِ فِي غَزْوَةِ ذَاتِ الْعُشَيْرَةِ قَالَ فَاضْطَجَعْنَا فِي صَوْرٍ مِنَ النَّخْلِ فِي دَقْعَاءَ مِنَ التُّرَابِ فَنِمْنَا فَوَاللَّهِ مَا أَهَبَّنَا إِلَّا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يُحَرِّكُنَا بِرِجْلِهِ وَقَدْ تَتَرَّبْنَا مِنْ تِلْكَ الدَّقْعَاءِ فَيَوْمَئِذٍ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ لِعَلِيٍّ يَا أَبَا تُرَابٍ
It is narrated from Sayyiduna Ammar bin Yasir (may Allah be pleased with him), he says: I and Sayyiduna Ali (may Allah be pleased with him) were companions during the expedition of Dhat al-‘Ushayrah. So we lay down and slept on the ground under the shade of some date-palm trees. By Allah! None woke us except the Messenger of Allah (peace and blessings be upon him); he moved us with his leg, while we were covered in dust. On that day, the Messenger of Allah (peace and blessings be upon him) said to Sayyiduna Ali (may Allah be pleased with him): O Abu Turab! (the man of dust).