As for the questions that pertain to the time at which one must abstain:

All the scholars agree that its end is the setting of the sun, in keeping with the Almighty’s words,
“Then complete the fast until nightfall” (Q. 2:187).

They disagreed, however, about its beginning. The majority maintain that it starts with the appearance of the second, spreading, white dawn, for this is decisively established from the Messenger of Allah—may Allah bless him and grant him peace—who defined the time by that spreading light. It also accords with the outward sense of the verse, “until the white thread becomes distinct to you from the black thread of dawn” (Q. 2:187).

A small group diverged, holding that the intended dawn is the red glow that appears after the white, analogous to the red dusk; this view is reported from Ḥudhayfa and Ibn Masʿūd.

The source of the disagreement lies in the conflicting reports on the matter and in the fact that the term “dawn” (fajr) can designate both the white and the red light.

Among the traditions cited in evidence is the report of Zir from Ḥudhayfa, who said: “I ate the pre-dawn meal with the Prophet—peace and blessings be upon him—and, had I wished, I could have said it was already daytime, except that the sun had not yet risen.”

Abū Dāwūd also records, through Qays ibn Ṭalq from his father, that the Prophet—peace and blessings be upon him—said: “Eat and drink; let not the bright, ascending glow alarm you. Rather, eat and drink until the redness stretches across the horizon.” Abū Dāwūd then remarks, “This narration is unique to the people of Yamāmah and is anomalous, for the Almighty’s statement, ‘until the white thread becomes distinct to you,’ is explicit—or nearly so—on the point.”

Those who identify the decisive dawn with the spreading white light—the relied-upon view of the majority—differ over the precise moment at which eating becomes unlawful. Some say it is the very moment the dawn actually rises. Others contend that it is when the dawn becomes evident to the observer; whoever has not noticed it may continue eating until it is plainly visible, even if it has technically risen.

The practical consequence of this difference is clear: should it later emerge that the dawn had indeed risen while a person assumed it had not, anyone who sets the boundary at the actual rising obliges that person to make up the fast, whereas those who set it at the acquisition of knowledge do not.

The root of the dispute is the possible ambiguity in the verse, “and eat and drink until the white thread becomes distinct to you from the black thread of dawn” (Q. 2:187). Does the duty to abstain hinge on the act of distinction itself, or on the thing distinguished? For Arabic usage allows a figurative substitution whereby what follows a thing is stated in place of the thing itself. It is as though the Almighty said, “Eat and drink until the white thread becomes distinct to you from the black thread of dawn,” because once it becomes distinct in itself, it necessarily becomes distinct to us. Thus the phrase “to you” is what gave rise to the disagreement, for it may become distinct in