1633An NasaiSahih (Darussalam)أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ سَعِيدٍ، عَنْ إِسْحَاقَ بْنِ سُلَيْمَانَ، عَنْ أَبِي سِنَانٍ، عَنْ أَبِي حُصَيْنٍ، عَنْ شَقِيقٍ، عَنْ حُذَيْفَةَ، قَالَ كُنَّا نُؤْمَرُ بِالسِّوَاكِ إِذَا قُمْنَا مِنَ اللَّيْلِ .It was narrated that Hudhaifah said:"We were commanded to use the siwak when we got up to pray at night."Reference: Sunan an-Nasa'i 1623 In-book : Book 20, Hadith 26 English translation : Vol. 2, Book 20, Hadith 1624