بِسمِ اللَّهِ الرَّحمٰنِ الرَّحيمِ
وَالشَّمسِ وَضُحاها
By the sun and her forenoon splendour.
EXEGESIS
Ḍuḥāhā (her forenoon splendour) means the issuing of the sun when it rises. According to Rāghib, al-ḍuḥā is the extension of sunlight, but later it was used to mean the time when the day rises and the sunlight spreads after sunrise.
According to Subḥānī, what is more appropriate to say is that it refers to the extension of the rays and light of the sun considering how significant sunlight is in maintaining life on earth. According to him, ṣubḥ is used to indicate the time between fajr and sunrise, while ḍuḥā refers to the early morning after sunrise.
It has been attributed to Qatādah that ḍuḥā in this verse refers to the whole day, and thus the verse would be swearing by the sun and the day which is lit by it. This meaning has also been supported by al-Farrāʾ and Ibn Qutaybah.
Yet another opinion is that ḍuḥā here refers to the heat of the sun.
EXPOSITION
This chapter uniquely begins with eleven oaths, the most of any chapter in the Quran. The purpose of oaths in the Quran is to emphasise not only the subject of the oath but to show the importance of the object of the oath as well, for God does not swear by that which is petty. In this chapter, God swears by eleven objects to show the magnanimity of the subject, the purification of the soul: One who purifies it is felicitous (verse 9).
In this verse, God swears by two things; By the sun as a great and magnificent creation of God which is visible every day by everyone, with all its splendour. And by its light, which is the source of great blessing and has considerable impact on maintaining life on earth.
[1] Raghib, p. 292.
[2] Munyah, 30/373.
[3] Munyah, 30/373.
[4] Tabrisi, 10/754.
[5] Razi, 31/174.
[6] Razi, 31/174.