In Surah Al-Furqan (The Criterion), Allah describes the phenomenon of the shadow and its relationship with the Sun:
"Have you not considered your Lord - how He extends the shadow, and if He willed, He could have made it stationary? Then We made the sun for it an indication. Then We seize it to Us with a gentle seizing." (Al-Furqan 25:45-46)
This passage describes with remarkable precision the phenomenon of the shadow, its variation during the day and its link with the Sun.
The shadow and the course of the Sun
The shadow of an object varies in length and direction during the day, according to the apparent position of the Sun in the sky. This variation is due to the Earth's rotation on its axis.
The Quran states that the Sun is the "guide" of the shadow: it is indeed the position of the Sun that determines the direction and length of the shadow. In the morning, when the Sun is low in the east, shadows are long and point west. At noon, when the Sun is at its highest, shadows are shortest. In the evening, they lengthen again pointing east.
This Quranic description, which makes the Sun the "guide" of the shadow, corresponds exactly to the observed physical mechanism.
The variation of the shadow over the seasons
The length of the shadow at noon also varies over the seasons, due to the tilt of the Earth's axis and the apparent course of the Sun. In summer, the Sun is higher in the sky and noon shadows are shorter; in winter, the Sun is lower and shadows are longer.
This seasonal variation, linked to the movement of the Earth around the Sun, illustrates the precision of the cosmic order evoked in the verse.
"We seize it to Us": the shortening of the shadow
The expression "Then We seize it to Us with a gentle seizing" describes the progressive shortening of the shadow as the Sun rises in the sky. This phenomenon, observable daily, is described in the Quran with remarkable accuracy.
A sign of divine order
The verse invites contemplation of the regularity of natural phenomena — the course of the Sun, the variation of shadows — as so many signs of the order established by the Creator. Modern science, by explaining these mechanisms, only confirms the accuracy of this description.