Sunan Ibn Majah 474
It was narrated that `A'ishah said:
"The Messenger of Allah would fall asleep until he was breathing deeply, then he would get up and offer the prayer, and he did not perform ablution." (Hasan)
Tanafisi said: "Waki` said: 'She meant while he was prostrating (he would sleep).'"
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَعَلِيُّ بْنُ مُحَمَّدٍ، قَالاَ حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا الأَعْمَشُ، عَنْ إِبْرَاهِيمَ، عَنِ الأَسْوَدِ، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ يَنَامُ حَتَّى يَنْفُخَ ثُمَّ يَقُومُ فَيُصَلِّي وَلاَ يَتَوَضَّأُ ‏.‏ قَالَ الطَّنَافِسِيُّ قَالَ وَكِيعٌ تَعْنِي وَهُوَ سَاجِدٌ ‏.‏