(31) باب التَّقَدُّمِ قَبْلَ شَهْرِ رَمَضَانَ
It was narrated from Abu Hurairah that the Messenger of Allah said:
"Do not fast ahead of the month, except for a man who habitually fasts, and that day happenes to be one of his regular fasts." ' (ID)
Reference (ID): Sunan an-Nasa'i 2172 (ID)
In-book reference (ID): Book 22, Hadith 83 (ID)
English translation (ID): Vol. 3, Book 22, Hadith 2174 (ID)