Surah Yunus (10) — Ayah 5

5. He is the One Who made the sun a radiant light [7] and the moon a light, and determined phases for the moon [8] so that you may know the number of years and the calculation of time [9]. Allah has created all this for a true purpose [10]. He explains His signs in detail for people who have knowledge.

[7]
The Difference Between Ḍiyā’ and Nūr:

The difference between ḍiyā’ and nūr is that the word nūr is general, while ḍiyā’ is specific. In other words, ḍiyā’ is also a type of nūr. Nūr contains light and brightness, whereas ḍiyā’ contains, in addition to light and brightness, heat, warmth, and a reddish hue in its color. The Noble Quran generally uses the word ḍiyā’ for the light of the sun and the word nūr for the light of the moon.

[8]
The Phases of the Moon:

According to the Ptolemaic theory of astronomy, astronomers have designated twenty-eight lunar mansions for the moon in the sky. In the era of the Prophet ﷺ, this astronomical theory was widely accepted and taught in educational institutions. Therefore, even if these same 28 phases are intended in this verse, there is no harm. However, most scholars interpret the “manāzil al-qamar” as the shapes of the moon, and their reasoning is derived from another verse
﴿ وَالْقَمَرَ قَدَّرْنٰهُ مَنَازِلَ حَتّيٰ عَادَ كَالْعُرْجُوْنِ الْقَدِيْمِ﴾ [36: 39]
in which, at the end, the crescent (the new or first night’s moon) is mentioned.

[9]
The Lunar Calendar and Its Characteristics:

From this, it is understood that the lunar calendar is the true calendar, not the solar one. Therefore, wherever the counting of a month or a period longer than that is required, from the perspective of Islamic law, it will be according to the lunar calendar, such as the days of ‘iddah and breastfeeding, the determination of periods in contracts, etc. Also, the rulings of Islam, such as Hajj, fasting, the sacred months, and the two Eids, are all connected to the lunar calendar. The prominent characteristics of the lunar calendar are that it is a simple and natural calendar, free from human interference (such as intercalation and its various types). The number of days in a month cannot be changed in it; the year will always have twelve months, and the principle of equality and universality for all people of the world is operative in it, and worldly customs and motives cannot influence it. (For further details, see my book ﴿الشمس والقمر بحسبان﴾.)

[10]
The Benefits of the Movement of the Sun and the Moon:

That is, the movement of the sun and the moon according to a fixed calculation is not meaningless; rather, it has many benefits. The first benefit is that you can determine the times of prayers and business hours from the movement of the sun, and when the period to be counted is less than a month, this period can be determined by the sun or the moon. However, when this period is more than a month, its calculation will be according to the moon, whose division is protected from human interference. In this way, you can keep track of periods for centuries. The second benefit is that the system of the movement of the sun, moon, and other stars is so interconnected, organized, and obedient to the command of Allah that even a moment’s advancement or delay is impossible. In this way, you can also prepare calendars for centuries to come. And the third, most important and real benefit is that you should reflect on the power and authority of the Being who created these things and bound them in their orbits in such a way, and see that the Being who can accomplish such magnificent feats—can He not create you again? This, in effect, is a second argument for the Resurrection.