Sunan an-Nasai Book 36, Hadith 3962

أَخْبَرَنَا إِسْحَاقُ بْنُ مَنْصُورٍ، قَالَ حَدَّثَنَا عَبْدُ الرَّزَّاقِ، قَالَ أَنْبَأَنَا ابْنُ جُرَيْجٍ، ‏{‏ عَنْ عَطَاءٍ، ‏}‏ قَالَ أَخْبَرَنِي ابْنُ أَبِي مُلَيْكَةَ، أَنَّ عَائِشَةَ، قَالَتِ افْتَقَدْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم ذَاتَ لَيْلَةٍ فَظَنَنْتُ أَنَّهُ ذَهَبَ إِلَى بَعْضِ نِسَائِهِ فَتَجَسَّسْتُ ثُمَّ رَجَعْتُ فَإِذَا هُوَ رَاكِعٌ أَوْ سَاجِدٌ يَقُولُ ‏ "‏ سُبْحَانَكَ وَبِحَمْدِكَ لاَ إِلَهَ إِلاَّ أَنْتَ ‏"‏ ‏.‏ فَقُلْتُ بِأَبِي وَأُمِّي إِنَّكَ لَفِي شَأْنٍ وَإِنِّي لَفِي آخَرَ ‏.‏

Aishah said:"I noticed that the Messenger of Allah was not there one night, and I thought that he had gone to one of his other wives. I looked for him then I came back, and there he was, bowing or prostrating and saying: 'Subhanaka wa bi hamdika la ilaha illa anta (Glory and praise be to You, there is none worthy of worship but You).' I said: 'May my father and mother be sacrificed for you; you were doing one thing and I was thinking of something else