horizontally, but rather vertically. True dawn, by contrast, spreads horizontally, extending from north to south.

The second distinction is that true dawn is not followed by darkness; rather, the light steadily increases until sunrise. False dawn, however, is followed by darkness after its light appears. This is why it is called false dawn: it fades and disappears.

The third distinction is that true dawn is connected to the horizon, whereas a band of darkness lies between false dawn and the horizon. These are three visible distinctions on the horizon that people can recognize when they are out in the open countryside. In cities, however, they cannot discern them because artificial lights obscure these signs.

Allah swears by the dawn because it marks the beginning of the day and the transition from pitch darkness to radiant light. He also swears by it because none but Allah Almighty and Majestic can bring forth this dawn. As Allah Most High says:

“Say, ‘Have you considered: if Allah were to make the night perpetual over you until the Day of Resurrection, what god other than Allah could bring you light? Will you not then listen?’” [al-Qasas: 71]

Allah also swears by the dawn because important legal rulings depend upon it. One is that a fasting person must refrain: once dawn breaks, he must refrain if his fast is obligatory, or if it is voluntary and he wishes to complete it. Another is that the time for the dawn prayer begins. These are two momentous legal rulings, the more important of which is the beginning of the prayer time. In other words, we must take greater care to ascertain the dawn for the beginning of prayer time than for commencing abstention when fasting. If we were to err regarding abstention from the things that invalidate the fast, we would have proceeded on the basis of an established presumption—namely, that night was still continuing. But if we erred regarding the prayer and performed it before dawn, we would have no such presumption to support us, for the established presumption is that night continues and the prayer time has not yet begun. For this reason, if someone performed the dawn prayer before its prescribed time had begun—