It was narrated on the authority of Abu Hurayrah, may Allah be pleased with him, that the Prophet said: “No one of you should fast a day or two before Ramadan unless he has the habit of fasting voluntarily (and if his fasting coincides with that day) then he can fast that day.” [Al-Bukhari and Muslim]
It was also narrated that the Prophet said: “Do not fast one or two days before the month (of Ramadan) unless this marks a habit of anyone of you who used to fast (voluntarily) on it.” [At-Tirmithi]
Benefits and rulings:
First: The prohibition of fasting before Ramadan to be on the safe side with regard to Ramadan.
Scholars have said, “The Hadeeth means: ‘Do not fast directly before Ramadan with the intention of being on the safe side regarding the month of Ramadan.’”
At-Tirmithi said, “Acting in accordance with that, scholars dislike that a person fasts directly before the month of Ramadan, to be on the safe side. However, if someone is used to fasting voluntarily and his fasting coincides with those days then, according to scholars, there is no blame on him if he fasts those days.”
Second: The prohibition of absolute voluntary fasting before Ramadan.
Third: An exception applies to the person who regularly fasts those days for expiation or a vow, and also the person who always fasts voluntarily on those days, like fasting Mondays and Thursdays.
Fourth: The soundest opinion expressed about the wisdom behind this prohibition is that fasting is contingent on viewing the crescent. Hence, anyone who fasts one or two days before the vision is established discredits this ruling and rejects the texts that make fasting contingent on viewing the crescent.
Fifth: This Hadeeth (narration) refutes the claim of the Raafidhah (a deviant sect), as they believe in fasting before viewing the crescent.
Sixth: The Hadeeth indicates leaving a time span between obligatory and voluntary acts of worship.
As regards fasting, voluntary fasting during Sha‘baan and obligatory fasting in Ramadan must be separated by forbidding fasting on the doubtful days. Similarly, obligatory fasting at the end of Ramadan and voluntary fasting at the beginning of Shawwaal must be separated by forbidding fasting on the day of ‘Eed.
Ibn ‘Abbaas, may Allah be pleased with him, and a group of the righteous predecessors recommended separating the obligatory prayer and the voluntary prayer by talking, standing, walking, moving forward or backward.
Seventh: The obligation of adhering to the Sharee‘ah (Islamic legislation) as it is, without any additions or reductions, as this leads to extreme practices in religion or even leaving the religion. This point is understood from the prohibition of fasting directly before Ramadan to be on the safe side regarding it.