مُوَطَّأُ مَالِكٍ
Muwatta Malik 146
Purity
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ حُمَيْدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ، عَنْ أَبِي هُرَيْرَةَ، أَنَّهُ قَالَ لَوْلاَ أَنْ يَشُقَّ، عَلَى أُمَّتِهِ لأَمَرَهُمْ بِالسِّوَاكِ مَعَ كُلِّ وُضُوءٍ .
Yahya related to me from Malik from Ibn Shihab from Humayd ibn Abdar-Rahman ibn Awf that Abu Hurayra said, "Were it not that he would be overburdening his community he (the Messenger of Allah, (ﷺ),) would have ordered them to use a tooth-stick with each wudu."
Arabic/English book reference: Book 2, Hadith 117