especially those who hold that dates may differ from place to place. For if some or all of the delegations see the crescent and then arrive in Mecca, while it has not been sighted near Mecca, their position entails consequences for the pilgrimage rites that are manifestly contrary to Islam. Owing to the flaws we have mentioned, this position has taken various forms. What we have explained, however, achieves the unity prescribed by the Sharia: each community unites upon whatever it can agree upon. If someone differs from them without their knowing it, because he alone knows something they do not, this does no harm. The problem lies in awareness of division and disagreement.

To clarify this, one must understand the crescent moons. Allah says:

“They are measurements of time for the people and for Hajj.”

This indicates that He meant what is known through sight or hearing. Hence al-Shāfiʿī, and Ahmad according to one of the two reports from him, held that if the sky is clear and no one has sighted the crescent, it is not a day of doubt: there is no uncertainty concerning the crescent, even if there is uncertainty as to whether it has risen.

This can be explained in two ways:

First: the word hilāl (crescent) follows the pattern fiʿāl. In Arabic, this pattern denotes something by means of which an action is performed: izār is what one wraps around the waist; ridāʾ is what one wears over the upper body; rikāb is what is used for riding; wiʿāʾ is that in which, or by means of which, something is contained; simād is what is used to fertilize the soil; ʿisāb is what is used for binding; and sidād is what is used to plug an opening. This is a common and regular pattern in nouns.