The Chain of Oaths (91:1-8)
“By the sun and its brightness / By the moon when it follows it / By the day when it displays it / By the night when it covers it / By the sky and He who constructed it / By the earth and He who spread it / By the soul and He who proportioned it and inspired it [with discernment of] its wickedness and its righteousness.”
The structure escalates: cosmic realities → creation itself → the human soul. By swearing by all of these and then by the soul, the Quran establishes that the soul’s moral reality is of the same cosmic weight as the sun and the earth. The stakes of what you do with your soul are not private; they are cosmological.
Fa-alhamaha fujuraha wa-taqwaha (and inspired in it its wickedness and its righteousness): the soul was taught its two paths — not made incapable of either one. This verse is key to Islamic ethics: the capacity for both fujur (transgression) and taqwa (God-consciousness/righteousness) is innate, divinely instilled, not socially constructed.
Qad Aflaha man Zakkaha (91:9)
“He has succeeded who purifies it.”
Aflaha (succeeded/flourished) — from the root f-l-h, also the root of al-falah (success/prosperity) in the adhan: hayya ‘ala al-falah (come to success). The adhan’s promise and this surah’s conclusion are the same word: the success called to in the prayer is the success achieved by soul-purification.
Zakkaha (purifies it) — same root as zakah (alms tax), tazkiyah (spiritual purification): the word implies both cleansing and growth. A purified soul is not merely a cleaned soul but a cultivated, flourishing one.
The Thamud Example (91:11-15)
The people of Thamud transgressed when the greatest wrongdoer among them was sent out to kill the she-camel (Salih’s sign). Their tadsiyah — the corruption of their collective soul — produced a single act of transgression that brought collective punishment: “So their Lord brought down upon them a destructive punishment for their sin and leveled it [i.e., Thamud] — equalized [with the earth]. And He does not fear the consequence thereof.” (91:14-15)
See also: Tazkiyah, Sulook, Akhlaq, Signs Of Qiyamah, Quran Sciences, Tafsir Overview