a month, or ten days of it, or fasting on alternate days, or fasting on the Day of ‘Arafah or ‘Āshūrā’ when either falls on a Friday. Fasting on Friday is not disliked in any of these cases.

If it is objected: “How, then, do you deal with the hadith of ‘Abd Allāh ibn Mas‘ūd: ‘Rarely did I see the Messenger of Allah (peace and blessings be upon him) refrain from fasting on (1) a Friday’?” It was related by the compilers of the Sunan collections (2).

The reply is: We accept it if it is authentic, and it must then be understood as referring to his fasting Friday together with the day before or after it. We reject it if it is not authentic, for it is among the singular reports. Al-Tirmidhī said: “It is a singular hadith.”

Section
His guidance (peace and blessings be upon him) concerning i‘tikāf (devotional retreat)

Since the soundness of the heart and its steadfastness on its journey to Allah depend upon its being wholly focused on Allah and gathering its scattered concerns through turning entirely to Him—for nothing gathers the heart’s scattered concerns except turning to Allah—and since excessive eating, drinking, socializing, speech, and sleep further scatter it, disperse it in every direction, and cut it off from its journey to Allah, weaken it, impede it, or bring it to a halt = the mercy of the Almighty, the Most Merciful, towards His servants required (3) that He prescribe for them fasting that dissipates excess food and drink and purges the heart of the mingled desires that impede its journey to Allah. He prescribed it in a measure suited to their welfare, so that the servant benefits from it in this world and the Hereafter, without suffering harm or being cut off from what benefits him now or in the future.