Allah, Exalted is He, decreed that the sighting of the new moon (crescent) should be usedto determine the timing of the lunar months. The sighting of the crescent marks the end of one lunar month and the beginning of another. Based on this sighting, many religious obligations are determined, such as fasting and Hajj. In this hadeeth, Aboo Hurayrah (may Allah be pleased with him) stated that the Prophet ﷺ forbade Muslims from fasting the day or two days before the month of Ramadan (the last day or two days of Sha’baan). It is not prescribed for Muslims to observe fasting at the end of Sha’baan as a precaution, because theobligatory fastingis contingent on the sighting of the moon and there should beno Takalluf (i.e., overburdening oneself with undue duties) involved, whether the sky is clear or cloudy. He ﷺ specifically mentioned the last two days of Sha‘baan because doubt may arise on those two days if the sky happened to be cloudy (and it was not possible to sight the new moon clearly) for two or three months. He ﷺforbade fasting on these days for two reasons.First, for fear that this would involve adding extra days to the month of Ramadan.It was also forbidden to fast on the Day of ‘Eid for the same reason, and to avoid following the example of the People of the Book,who had fallen into adding to their obligatory fasting based on their personal whims and preferences. This is whyit is prohibited to fast on the Day of Doubt, i.e., the last day of Sha‘baan. Second, the religion made the obligatory fasting in Ramadancontingent on the sighting of the moon and fasting on the preceding day or two days implies challenging the rulings of Islam. Then he ﷺmade an exception from this prohibition if a person is used to fasting on a specific day, such as the case of someone who habitually observes fasting on alternate days or on Mondays, if such were to coincide with these two days. In this case, there is no impediment to fasting on these days because it does not fall under the category of forbidden fasting (as intended in the hadeeth) as per the laws of Islam. .