Its limits, therefore, cannot be determined by prevailing linguistic usage; rather, it is an act of worship, and acts of worship (1) must, in their qualities and prescribed amounts, return to the Lawgiver (2) just as their very institution comes from Him.

For if recourse were allowed to the people’s custom—whether concerning the act itself or what they call “lightness”—the fixed, canonical prayer that one is commanded (3) to perform at most times, when no factors demand lengthening or shortening, would end up varying so widely (4) and without regulation that each generation and land, indeed every neighborhood and alleyway, even every mosque, would develop its own understanding of the term and its own habitual practice, at odds with everyone else’s.

This runs counter to the command of Allah and His Messenger, for he said:

“Pray as you have seen me pray.” (5)

He did not say, “Pray as the people of your land call it light,” or “as they are accustomed to pray.” I know of no scholar who has ever said such a thing, for it would lead to altering the Sacred Law and extinguishing the Sunnah, whether by addition or omission. All the other reports from the Companions bear this out.

Muslim narrates in his Ṣaḥīḥ from Zuhayr (6), on the authority of Simāk ibn Ḥarb (7), who said: