Fasting (Kitab Al-Siyam)
Dawud :: Book 13 : Hadith 2431
Narrated One of the wives of the Prophet:
Hunaydah ibn Khalid narrated from his wife on the authority of one of the wives of the Prophet (peace_be_upon_him) who said: The Apostle of Allah (peace_be_upon_him) used to fast the first nine days of Dhul-Hijjah, Ashura' and three days of every month, that is, the first Monday (of the month) and Thursday.