Sunan Ibn Majah 541
It was narrated that Abu Darda' said:
"The Messenger of Allah came out to us with water dripping from his head, and he led us in prayer wearing a single garment, placing its one end on the right shoulder, and the other end on the other shoulder. When he finished praying, 'Umar bin Khattab said to him: 'O Messenger of Allah, did you lead us in prayer wearing a single garment? He said: 'Yes, I perform prayer in it, and in it I (i.e. I had sexual intercourse in it)."
حَدَّثَنَا هِشَامُ بْنُ خَالِدٍ الأَزْرَقُ، حَدَّثَنَا الْحَسَنُ بْنُ يَحْيَى الْخُشَنِيُّ، حَدَّثَنَا زَيْدُ بْنُ وَاقِدٍ، عَنْ بُسْرِ بْنِ عُبَيْدِ اللَّهِ، عَنْ أَبِي إِدْرِيسَ الْخَوْلاَنِيِّ، عَنْ أَبِي الدَّرْدَاءِ، قَالَ خَرَجَ عَلَيْنَا رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ وَرَأْسُهُ يَقْطُرُ مَاءً فَصَلَّى بِنَا فِي ثَوْبٍ وَاحِدٍ مُتَوَشِّحًا بِهِ قَدْ خَالَفَ بَيْنَ طَرَفَيْهِ فَلَمَّا انْصَرَفَ قَالَ عُمَرُ بْنُ الْخَطَّابِ يَا رَسُولَ اللَّهِ تُصَلِّي بِنَا فِي ثَوْبٍ وَاحِدٍ قَالَ ‏
"‏ نَعَمْ أُصَلِّي فِيهِ وَفِيهِ ‏"‏ ‏.‏ أَىْ قَدْ جَامَعْتُ فِيهِ ‏.‏