Sahih al-Bukhari 11:15
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.
Reference
Sahih al-Bukhari 11:15
In-book reference
Book 11, Hadith 15
Arabic Text
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.