Muhammad ibn ‘Abbaad said:
I asked Jaabir, "Did the Prophet ﷺ forbid fasting on Fridays?" He replied, "Yes." (Other narrators added, "If he intends to fast only that day.").
Commentary :
The Prophet ﷺexplained the Laws of Islam rulings on voluntary fasting, and clarified the appropriate way to fast some days, including Fridays.
In this hadeeth, the Taabi’ee (a Muslim who saw at least one of the Companions) Muhammad ibn ‘Abbaad asked Jaabir ibn ‘Abdullah(may Allah be pleased with them): “Did the Prophet ﷺ forbid voluntary fasting on Fridays only?” He (may Allah be pleased with him) replied in the affirmative. It is noteworthy that the prohibition in this regard does not apply to the one who habitually fasts on alternate days, for example, and one of these fasts happens to coincide with Friday, or someone who vows to fast on the day when a sick loved one would be blessed with recovery and it coincided with Friday. Fasting on Friday is not prohibited in these cases. It is also prescribed to fast on Fridays if one fasts the day before or after it as well, as stated in the hadeeth narrated on the authority of Aboo Hurayrah (may Allah be pleased with him) and compiled in Saheeh Al-Bukhaaree and Saheeh Muslim.
The wisdom behind forbidding fasting on Friday is that it is a day of supplication, remembrance of Allah, and worship. A Muslim devotes his day to performing Ghusl, going early to the mosque, waiting for the Friday prayer, listening to the Khutbah, and reciting Dhikr (i.e. remembrance of Allah) abundantly afterward, because Allah, Exalted is He, Says (what means): {And when the prayer has been concluded, disperse within the land and seek from the bounty of Allah, and remember Allah often that you may succeed.} [Quran 62:10].These are examples of the worshipful acts performed on that blessed day. Therefore, it is deemed forbidden to fast on that day to be inducive to performing these acts energetically and joyfully, and enjoying their performance without boredom or tedium. This is similar to the prohibition of fasting on the Day of ‘Arafah for a pilgrim. The Sunnah for a pilgrim is to refrain from fasting on that blessed day for the same wisdom. When a person fasts a day before or after Friday as well, this compensates for any inactivity or negligence that may occur in the performance of his duties on Friday. It is also possible that the wisdom behind the Prophet’s ﷺprohibition of fasting on Friday was for fear that people would continue to observe fasting on Fridays habitually and it would be deemed obligatory on them, as he ﷺ feared observing night prayer regularly lest it be deemed obligatory on Muslims. He ﷺ also feared that Muslims would venerate Fridays in the same manner the Jews and Christians venerated Saturdays and Sundays, giving up work and copying their unprescribed manner of veneration. Therefore, he ﷺ ordered that Muslims should refrain from fasting on Fridays, believing that blocking the ways leading to unfavorable results is better and more rewardable than completing the days that he ﷺ had intended to fast for the sake of Allah, Exalted is He. It could also be because Friday is a day of ‘Eid (i.e., ritual celebration) for Muslims.
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