and Ibn ‘Umar, which is transmitted both as a report traced back to the Prophet and as a statement of a Companion:

“No fast is valid for anyone who has not formed the intention to fast the night before.”

The third view is that an obligatory fast is valid only if the intention is formed the night before, as indicated by the hadith of Hafsah and Ibn ‘Umar. This is because fasting is required throughout the entire period, and an intention does not apply retroactively. A voluntary fast, however, is valid with an intention formed during the day, as indicated by the Prophet’s words:

“Then I am fasting.”

Likewise, obligatory prayers require certain essential elements—such as standing and remaining on the ground—that are not required in voluntary prayers. Thus Allah grants His servants greater latitude in the ways they may perform voluntary worship. Voluntary acts of worship always allow greater latitude than obligatory ones.

As for their fasting on the day of ‘Āshūrā’, if it was obligatory, it only became obligatory for them during the day, because they had not known of it beforehand. The report transmitted by some later writers on juristic disputation that this occurred in Ramadan is false and has no basis.

This is the most balanced view, and it is the position of al-Shāfi‘ī and Ahmad. Their positions varied, however, on whether a voluntary fast is valid if the intention is formed after solar noon. The stronger view is that it is valid, as reported from the Companions.

Their followers differed concerning the reward: is it the reward for a full day, or only from the time