مختصر صحيح مسلم
Mukhtasar Sahih Muslim
Issues of Fasting
Virtue of fasting in Muharram.
Narrated Abu Huraira (may Allah be pleased with him): The Messenger of Allah (peace and blessings of Allah be upon him) said: After the fasts of Ramadan, the most virtuous of all fasts are those of Muharram, which is the month of Allah, and after the obligatory prayers, the most virtuous prayer is the night (Tahajjud) prayer.
تخریج الحدیث: