(70) باب صَوْمِ النَّبِيِّ صلى الله عليه وسلم - بِأَبِي هُوَ وَأُمِّي - وَذِكْرِ اخْتِلاَفِ النَّاقِلِينَ لِلْخَبَرِ فِي ذَلِكَ
It was narrated from 'Ubaidullah that:
he heard Ibn 'Abbas, when he was asked about the fast of 'Ashura' say: "I do not know that the Prophet fasted any day because of its virtue, except this day" meaning the month of Ramadan and the day of Ashura.' (RU)
Reference (RU): Sunan an-Nasa'i 2370 (RU)
In-book reference (RU): Book 22, Hadith 281 (RU)
English translation (RU): Vol. 3, Book 22, Hadith 2372 (RU)