عَنْ ثَابِتٍ عَنْ أَنَسِ بْنِ مَالِكٍ رَضِيَ اللَّهُ عَنْهُ قَالَ: صَلَّى بِنَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ تَطَوُّعًا، قَالَ: فَقَامَتْ أُمُّ سُلَيْمٍ وَأُمُّ حَرَامٍ خَلْفَنَا قَالَ ثَابِتٌ لَا أَعْلَمُهُ إِلَّا قَالَ وَأَقَامَنِي عَنْ يَمِينِهِ فَصَلَّيْنَا عَلَى بِسَاطٍ
It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him), he says: The Messenger of Allah (peace and blessings be upon him) led us in a voluntary prayer, Lady Umm Sulaym (may Allah be pleased with her) and Lady Umm Haram (may Allah be pleased with her) stood behind us, and the Prophet (peace and blessings be upon him) made me stand on his right side. We performed the prayer on a mat.