…nor should he delay or become sluggish; rather, he must pay it with a willing heart, regarding it not as a liability or a loss but as a personal gain. These three obligations together constitute din al-qayyimah (the upright religion). The word din means “religious way,” while al-qayyimah is an adjective whose qualified noun is omitted—i.e., “the religion, the upright creed.” Thus the verse furnishes proof for the duties of prayer and zakah and explains true monotheism. (40) Fasting is obligatory only for Muslims. If unbelievers were to fast, it would not be valid for them until they testify that there is no deity but Allah and that Muhammad is the Messenger of Allah ﷺ. As long as they remain in disbelief, acts of worship—fasting or otherwise—bring them no benefit. Hence the command is addressed exclusively to the believers, for they alone respond, their fasting is valid, and their fasting is accepted. “Kutiba ʿalaykumu s-siyam” (fasting has been prescribed for you): the verb kutiba here means “has been made obligatory,” just as in “kutiba ʿalaykumu l-qital” (2:216, fighting has been made obligatory for you). Throughout the Quran, kutiba conveys the sense of religious obligation.