Surah Al-Qasas, Ayah 73

Night and Day are among the Blessings of Allah and are Signs of Tawhid

Allah reminds His servants of His favors towards them by subjugating for them the night and day, without which they could not survive. He explains that if He made the night continuous, lasting until the Day of Resurrection, that would be harmful for them and would cause boredom and stress. So He says:

مَنْ إِلَـهٌ غَيْرُ اللَّهِ يَأْتِيكُمْ بِضِيَآءٍ

(which god besides Allah could bring you light) meaning, `with which you could see things and which would bring you relief'

أَفَلاَ تَسْمَعُونَ

(Will you not then hear) Then Allah tells us that if He had made the day continuous, lasting until the Day of Resurrection, that would also be harmful for them and their bodies would get tired from so much movement and activity. Allah says:

قُلْ أَرَ‌أَيْتُمْ إِن جَعَلَ اللَّـهُ عَلَيْكُمُ اللَّيْلَ سَرْ‌مَدًا إِلَىٰ يَوْمِ الْقِيَامَةِ مَنْ إِلَـٰهٌ غَيْرُ‌ اللَّـهِ يَأْتِيكُم بِضِيَاءٍ ۖ أَفَلَا تَسْمَعُونَ ﴿71﴾ قُلْ أَرَ‌أَيْتُمْ إِن جَعَلَ اللَّـهُ عَلَيْكُمُ النَّهَارَ‌ سَرْ‌مَدًا إِلَىٰ يَوْمِ الْقِيَامَةِ مَنْ إِلَـٰهٌ غَيْرُ‌ اللَّـهِ يَأْتِيكُم بِلَيْلٍ تَسْكُنُونَ فِيهِ ۖ أَفَلَا تُبْصِرُ‌ونَ ﴿72﴾

Say, "Tell me, if Allah makes night continuing upon you forever upto the Day of Judgment, which god, other than Allah, would bring to you light? Then do you not listen?" Say, "Tell me, if Allah makes the day continuing upon you forever upto the Day of Judgment, which god, other than Allah, would bring to you night in which you may have comfort. Then, do you not see?" 28:71-72.

The earth, which is inhabited by human beings, has innumerable wonderful aspects. One of these is that it is constantly revolving around the Sun. Its axial rotation as it passes around the sun is such that it completes one full circle in twenty four hours. This is what produces the phenomenon of the repeated alternation of day and night. Had it not been for this axial rotation of the earth, there would have been perpetual night in half portion of the earth and perpetual day in the other half. The result of this would have been that the comfortable earth we know would have become a punishment chamber horrible beyond expression. The constant rotation of the earth in space with perfect precision is so great a phenomenon that even the combined efforts of all men and all jinn could never have sufficed to bring it into existence. Nobody except the All Powerful God is capable of setting in motion such a great event. In view of this, it would be most misguided of man, to experience feelings of fear and love for anybody other than the One and Only God.