and clear proofs of guidance and criterion. So whoever sights [the new moon of] the month, let him fast it; and whoever is ill or on a journey — then an equal number of other days. Allah intends for you ease and does not intend for you hardship and [wants] for you to complete the period and to glorify Allah for that [to] which He has guided you; and perhaps you will be grateful} (Al-Baqarah: 185).

Whoever fasts less than thirty [days] is defective according to the narration; and if it does not coincide with the Covenant (Al-'Ahd), he has erred and has not fasted.

As for the saying of the Almighty: {And upon those who are able to fast, a ransom [is due] — the feeding of a poor person} (Al-Baqarah: 184): that is because a group of the Imams used to break their fast while they were [in a state of inward] fasting, then this verse was ablated (nuskhat) and the ransom for fasting was prohibited.

The totality is the month of Ramadan; it is named so, and its days are thirty days and its nights are thirty nights, and within it is the Night of Power (Laylat al-Qadr), which is better than a thousand months.

In the reading of Ibn Mas'ud: {Indeed, We sent it down on a blessed night. Indeed, We were ever sending it down. Therein is distinct every matter of wisdom} (Ad-Dukhan: 3-4). And the saying of the most Majestic of Speakers: {Indeed, We sent it [the Quran] down during the Night of Power} (Al-Qadr: 1). It [the Night] has a named Person (Shakhs musamma).