Ash-Shams الشمس "The Sun" is the 91st surah of the Qur'an, with 15 ayat or verses. It opens with a series of solemn oaths sworn on various astronomical phenomena, the first of which, "by the sun", gives the sura its name, then on the human soul itself. It then describes the fate of Thamud, a formerly prosperous but now extinct Arab tribe. The prophet Saleh urged them to worship God alone, and commanded them in God's name to preserve a certain she-camel; they disobeyed and continued to reject his message; they killed the she-camel and God destroyed them all except those who had followed Salih

Summary

• 1-10 Oaths that man’s happiness and misery depends on the purity or corruption he hath wrought in it
• 11-15 Thamúd destroyed for rejecting their prophet[1

Name of the surah

Jalaluddin Al-Suyuti co-author of the classical Sunni tafsīr known as Tafsir al-Jalalayn suggests that some of the sūrahs have been named using incipits (i.e. the first few words of the surah). The Surah has been so designated after the word ash-shams with which it opens. Hamiduddin Farahi wrote that some sūrahs have been named after some conspicuous words used in them.[2] Touched by an Angel: Tafseer Juz ‘Amma is an AlMaghrib Institute Tafsir course[3] which further investigates that the sun (ash-shams) is mentioned in several surahs; the reason why is this one called Surah Shams is because, in it, the sun is mentioned four times. Allah says:
91:1 وَالشَّمْسِ وَضُحَاهَا
91:2 وَالْقَمَرِ إِذَا تَلَاهَا
91:3 وَالنَّهَارِ إِذَا جَلَّاهَا
91:4 وَاللَّيْلِ إِذَا يَغْشَاهَا

Translation: By the sun and its brightness, and [by] the moon when it follows it. And [by] the day when it displays it, and [by] the night when it covers it. [Surah Ash-Shams, verses 1-4]. Notice “it,” “it,” “it,” … in Arabic, the pronoun used is haa (هَا), which is feminine. And all the other nouns referred to are masculine; which only leaves Ash-Shams–the sun–which is a feminine word; that’s the “it” referred to in the first four ayaat.[4]

Translation (Sahih internatin from quran.com)

1. By the sun and its brightness
2. And [by] the moon when it follows it
3. And [by] the day when it displays it1
4. And [by] the night when it covers [i.e., conceals] it
5. And [by] the sky and He who constructed it
6. And [by] the earth and He who spread it
7. And [by] the soul and He who proportioned it
8. And inspired it [with discernment of] its wickedness and its righteousness,
9. He has succeeded who purifies it,
10. And he has failed who instills it [with corruption].
11. Thamūd denied [their prophet] by reason of their transgression,
12. When the most wretched of them was sent forth
13. And the messenger of Allāh [i.e., Ṣāliḥ] said to them, "[Do not harm] the she-camel of Allāh or [prevent her from] her drink."
14. But they denied him and hamstrung1 her. So their Lord brought down upon them destruction for their sin and made it equal [upon all of them].
15. And He does not fear the consequence thereof.