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حَدَّثَنَا حَفْصُ بْنُ عُمَرَ قَالَ حَدَّثَنَا خَالِدُ بْنُ عَبْدِ اللَّهِ عَنْ حُصَيْنٍ عَنْ أَبِي وَائِلٍ عَنْ حُذَيْفَةَ رَضِيَ اللَّهُ عَنْهُأَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ إِذَا قَامَ لِلتَّهَجُّدِ مِنْ اللَّيْلِ يَشُوصُ فَاهُ بِالسِّوَاكِ

Hafs bin 'Umar narrated to us, Khalid bin Abdullah narrated to us, from Husain, from Abu Wa'il from Hudhaifah (may Allah be pleased with him), that when the Prophet peace and blessings be upon him stood for tahajjud at night, he would clean his mouth with the siwak.