the thirteenth, fourteenth, and fifteenth. Specifying the White Days is a specification of what is more virtuous, just as offering the prayer at the beginning of its time is more virtuous. That is, the best time for fasting the three days is the White Days. However, whoever fasts three days other than the White Days will attain the reward for fasting three days of every month, though not the specific reward of fasting the White Days, and will attain the reward of fasting for a lifetime.

Mondays and Thursdays, …

His statement, “Mondays and Thursdays,” means that it is recommended to fast on Mondays and Thursdays.

Fasting on Monday is more strongly recommended than fasting on Thursday. Thus, it is recommended for a person to fast on Monday and Thursday every week.

The Prophet, peace and blessings be upon him, explained the reason for this: “They are two days on which deeds are presented to Allah, exalted is He. He said: ‘I love for my deeds to be presented while I am fasting.’” (1) Hadith scholars differed over this hadith: some judged it weak and said that it cannot serve as proof; others, such as Ibn Khuzaymah, considered it authentic; and others remained silent regarding it, neither declaring it defective nor authenticating it. In any case, the jurists took it into consideration, cited it as supporting evidence, and used it as proof.