Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
bayhaqi:169Abū ʿAlī al-Ḥusayn b. Muḥammad al-Faqīh Nbā Abū Bakr b. Dāsah > Abū Dāwud > Muḥammad b. Bashhār > Muḥammad b. ʿAbdullāh al-Anṣārī

"The Prophet of Allah ﷺ would clean his teeth with the Siwak, then he would give me the Siwak in order to wash it. So I would first use it myself, then wash it and return it. (Using translation from Abū Dāʾūd 52)   

البيهقي:١٦٩أَخْبَرَنَا أَبُو عَلِيٍّ الْحُسَيْنُ بْنُ مُحَمَّدٍ الْفَقِيهُ أنبا أَبُو بَكْرِ بْنُ دَاسَةَ أنا أَبُو دَاوُدَ ثنا مُحَمَّدُ بْنُ بَشَّارٍ ثنا مُحَمَّدُ بْنُ عَبْدِ اللهِ الْأَنْصَارِيُّ ثنا عَنْبَسَةُ بْنُ سَعِيدٍ الْكُوفِيُّ الْحَاسِبُ قَالَ حَدَّثَنِي كَثِيرٌ عَنْ عَائِشَةَ

أَنَّهَا قَالَتْ كَانَ نَبِيُّ اللهِ ﷺ يَسْتَاكُ فَيُعْطِينِي السِّوَاكَ لِأَغْسِلَهُ فَابْدَأُ بِهِ فَأَسْتَاكُ ثُمَّ أَغْسِلُهُ وَأَدْفَعُهُ إِلَيْهِ  


See similar narrations below:

Collected by Abū Dāwūd
abudawud:52Muḥammad b. Bashhār > Muḥammad b. ʿAbdullāh al-Anṣārī

"The Prophet of Allah ﷺ would clean his teeth with the Siwak, then he would give me the Siwak in order to wash it. So I would first use it myself, then wash it and return it.  

أبو داود:٥٢حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ الأَنْصَارِيُّ حَدَّثَنَا عَنْبَسَةُ بْنُ سَعِيدٍ الْكُوفِيُّ الْحَاسِبُ حَدَّثَنِي كَثِيرٌ عَنْ عَائِشَةَ

أَنَّهَا قَالَتْ كَانَ نَبِيُّ اللَّهِ ﷺ يَسْتَاكُ فَيُعْطِينِي السِّوَاكَ لأَغْسِلَهُ فَأَبْدَأُ بِهِ فَأَسْتَاكُ ثُمَّ أَغْسِلُهُ وَأَدْفَعُهُ إِلَيْهِ