Sahih al-Bukhari 890
Narrated `Aisha:
`Abdur-Rahman bin Abi Bakr came holding a Siwak with which he was cleaning his teeth. Allah's 
Apostle looked at him. I requested `Abdur-Rahman to give the Siwak to me and after he gave it to me 
I divided it, chewed it and gave it to Allah's Messenger (ﷺ). Then he cleaned his teeth with it and (at that 
time) he was resting against my chest.
حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنِي سُلَيْمَانُ بْنُ بِلاَلٍ، قَالَ قَالَ هِشَامُ بْنُ عُرْوَةَ أَخْبَرَنِي أَبِي، عَنْ عَائِشَةَ ـ رضى الله عنها ـ قَالَتْ 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 فَقَصَمْتُهُ ثُمَّ مَضَغْتُهُ، فَأَعْطَيْتُهُ رَسُولَ اللَّهِ صلى الله عليه وسلم فَاسْتَنَّ بِهِ وَهْوَ مُسْتَسْنِدٌ إِلَى صَدْرِي‏.‏