Tafsir of Al-Furqan 25:45

Evidence of the existence of the Creator and the extent of His Power Here Allah begins explaining the evidence for His existence and His perfect power to create various things and pairs of opposites. Allah says:

ألم تر إلى ربك كيف مد الظل

Have you not seen how your Lord spread the shadow. Ibn Abbas, Ibn Umar, Abu Al-Aliyah, Abu Malik, Masruq, Mujahid, Sa`id bin Jubayr, An-Nakha`i, Ad-Dahhak, Al-Hasan, Qatadah, As-Suddi and others said, "This refers to the period from the beginning of the dawn until the sun rises.''

ولو شاء لجعله ساكنا

If He willed, He could have made it still, meaning, immobile, never changing. This is like the Ayat:

قل أرأيتم إن جعل الله عليكم اليل سرمدا

Say: "Tell me! If Allah made the night continuous for you...'' (28:71)

ثم جعلنا الشمس عليه دليﻼ

but We have made the sun its guide. means, were it not for the sun rising, it would not be there, for a thing can only be known in contrast to its opposite. Qatadah and As-Suddi said, "The sun is a guide which follows the shade until the shade disappears.''

ثم قبضناه إلينا قبضا يسيرا