Sahih al-Bukhari, Volume 5, Book 59, Hadith 731 (USC-MSA) ⓘ
Narrated `Urwa: `Aisha said, "Allah's Messenger in his fatal illness, used to ask, 'Where will I be tomorrow? Where will I be tomorrow?", seeking `Aisha's turn. His wives allowed him to stay wherever he wished. So he stayed at `Aisha's house till he expired while he was with her." `Aisha added, "The Prophet expired on the day of my turn in my house and he was taken unto Allah while his head was against my chest and his saliva mixed with my saliva." `Aisha added, "Abdur-Rahman bin Abu Bakr came in, carrying a Siwak he was cleaning his teeth with. Allah's Messenger looked at it and I said to him, 'O `AbdurRahman! Give me this Siwak.' So he gave it to me and I cut it, chewed it (it's end) and gave it to Allah's Messenger who cleaned his teeth with it while he was resting against my chest."
حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنِي سُلَيْمَانُ بْنُ بِلاَلٍ، حَدَّثَنَا هِشَامُ بْنُ عُرْوَةَ، أَخْبَرَنِي أَبِي، عَنْ عَائِشَةَ ـ رضى الله عنها ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَسْأَلُ فِي مَرَضِهِ الَّذِي مَاتَ فِيهِ يَقُولَ " أَيْنَ أَنَا غَدًا أَيْنَ أَنَا غَدًا " يُرِيدُ يَوْمَ عَائِشَةَ، فَأَذِنَ لَهُ أَزْوَاجُهُ يَكُونُ حَيْثُ شَاءَ، فَكَانَ فِي بَيْتِ عَائِشَةَ حَتَّى مَاتَ عِنْدَهَا، قَالَتْ عَائِشَةُ فَمَاتَ فِي الْيَوْمِ الَّذِي كَانَ يَدُورُ عَلَىَّ فِيهِ فِي بَيْتِي، فَقَبَضَهُ اللَّهُ وَإِنَّ رَأْسَهُ لَبَيْنَ نَحْرِي وَسَحْرِي، وَخَالَطَ رِيقُهُ رِيقِي ـ ثُمَّ قَالَتْ ـ دَخَلَ عَبْدُ الرَّحْمَنِ بْنُ أَبِي بَكْرٍ وَمَعَهُ سِوَاكٌ يَسْتَنُّ بِهِ فَنَظَرَ إِلَيْهِ رَسُولُ اللَّهِ صلى الله عليه وسلم فَقُلْتُ لَهُ أَعْطِنِي هَذَا السِّوَاكَ يَا عَبْدَ الرَّحْمَنِ. فَأَعْطَانِيهِ فَقَضِمْتُهُ، ثُمَّ مَضَغْتُهُ فَأَعْطَيْتُهُ رَسُولَ اللَّهِ صلى الله عليه وسلم فَاسْتَنَّ بِهِ وَهْوَ مُسْتَنِدٌ إِلَى صَدْرِي.
also referenced under: Book 64, Hadith 470 (In-Book) & Hadith 4450 (DarusSalam)