وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، أُغْمِيَ عَلَيْهِ فَذَهَبَ عَقْلُهُ فَلَمْ يَقْضِ الصَّلاَةَ ‏.‏ قَالَ مَالِكٌ وَذَلِكَ فِيمَا نَرَى - وَاللَّهُ أَعْلَمُ - أَنَّ الْوَقْتَ قَدْ ذَهَبَ فَأَمَّا مَنْ أَفَاقَ فِي الْوَقْتِ فَإِنَّهُ يُصَلِّي ‏.‏

Yahya related to me from Malik from Nafi that one time Abdullahibn Umar fainted and lost his senses and he did not make up theprayer. Malik commented, "We consider that that was because,and Allah knows best, the time had passed. Someone who recovers withinthe time has to pray." Translation Not Available

Book Ref: Muwatta Imam Malik Book 1 Hadith 24
Web Ref:  Muwatta Imam Malik Book 1 Hadith 24