The Quran establishes the divine origin of the Nafs, swearing by it and He who proportioned it. This oath highlights its intricate creation by Allah, who then inspired it [with discernment of its wickedness and its righteousness]. This endowment of discerning good from evil is fundamental to human free will and moral responsibility. As Ibn Kathir explains regarding “By Nafs, and Ma Sawwaha (Who apportioned it). Then He showed it its Fujur and its Taqwa”, Allah created the soul sound and well-proportioned upon its correct nature (Al-Fitrah), clarifying for it the path of good and evil. This is echoed in the Hadith, where the Prophet Muhammad ﷺ stated, "Every child that is born, is born upon the Fitrah, but his parents make him a Jew, a Christian, or a Zoroastrian" (Bukhari and Muslim). Furthermore, Allah affirms, "Verily I created My servants Hunafa' (as monotheists), but then the devils came to them and distracted them from their religion" Muslim 91:8.

This inherent capacity for both righteousness and wickedness means the Nafs is in a constant state of internal struggle. The Quran directly addresses this duality, as seen in Prophet Yusuf's invocation, 12:53. Ibn Kathir notes that the wife of the Aziz in Yusuf's story admitted, "I do not exonerate myself from blame, because the soul wishes and lusts, and this is what made me seduce him," affirming that the human self is inclined to evil unless Allah bestows His mercy. Ma'arif-ul-Quran elaborates on three states of the human self: Ammarah (inciting to evil), Lawwamah (reproaching), and Mutma'innah (at peace). The Ammarah self pulls towards bad deeds, but through the fear of Allah and repentance, it can evolve into the Lawwamah self, which hates evil and seeks forgiveness. Constant striving against the self can lead to the Mutma'innah state, where the urge for evil no longer remains. Prophets, by Divine grace, are blessed with the Mutma'innah state without prior striving.

A cornerstone of the Islamic concept of the soul is individual accountability. The Quran explicitly states that every soul earns not [blame except against itself, and no bearer of burdens will bear the burden of another]. This profound declaration, elaborated by Ibn Kathir, emphasizes that each person is solely responsible for their deeds, and no one will carry another's sins. This negates any notion of vicarious atonement, ensuring perfect justice. Ma'arif-ul-Quran discusses how this verse refutes the absurd claims of disbelievers who thought they could bear the sins of others. Furthermore, it highlights a legal principle that a child born out of wedlock is not affected by the parents' sin, citing a Hadith from Hakim based on `A'ishah.

On the Day of Judgment, this individual responsibility becomes acutely manifest. Allah declares, And each soul will be compensated [in full for what it earned, and they will not be wronged]. Ibn Kathir highlights the severity of this day, emphasizing that Allah will ask about the idols and rivals worshipped instead of Him. The day is further described as when 3:30 and what it has done of evil, it will wish that between itself and that evil was a great distance]. This vivid imagery, expounded upon by Ibn Kathir, illustrates the profound regret of those who committed evil, longing for their misdeeds to be far removed from them. It is a day when a soul will [then know what it has put forth and kept back], meaning it will comprehend all its deeds, whether actively done or passively neglected, as explained by Ma'arif-ul-Quran.

The journey of the soul extends beyond this worldly life, culminating in the Day of Judgment and the Hereafter. The Quran emphasizes the inevitability of this return to Allah, stating, 6:164. This return is depicted with solemnity: And every soul will come, with it a driver and a witness. Tafsir al-Jalalayn identifies these as angels – one to drive the soul to the gathering place and another to testify about its deeds. Ibn Kathir adds that `Uthman bin `Affan explained the "driver" as an angel leading to Allah, and the "witness" as an angel testifying to one's actions. This comprehensive record is maintained by "noble guardian angels" who record every word and deed, as indicated in “But verily, over you [are appointed angels” to watch you, Kiraman Katibin, they know all that you do]. Ma'arif-ul-Quran elaborates on this, explaining that hafiz (watcher) can refer to these recording angels or to protective angels appointed to shield man from calamities not decreed by Allah.

The moment of death itself is a profound transition, marked by the "stupor of death" (sakrat-ul-maut) which comes with truth, revealing the reality one sought to escape (“And the daze of death has to come with truth. That is what you tried to escape”). The Prophet Muhammad ﷺ himself experienced these pangs, wiping sweat from his face and saying, "Glory be to Allah! Verily, death has its stupor" (Bukhari, Muslim).

On the Day of Judgment, all secrets will be exposed and examined (The Day when all the secrets will be examined). Ibn Kathir explains this as beliefs, thoughts, motives, and hidden intentions being revealed. `Abdullah Ibn `Umar said that Allah would disclose all human secrets, with signs of good or bad deeds appearing on one's face. On this Day, “no soul will possess for another soul power to do a thing; and the command, that Day, is entirely with Allah”. This highlights the absolute sovereignty of Allah and the inability of anyone to intercede without His permission, as detailed by Ibn Kathir and Ma'arif-ul-Quran.

Islam lays immense emphasis on the purification (tazkiyah) of the Nafs. Allah swears by the soul and its proportioning, 91:9 and he has failed who instills it [with corruption]. Tafsir al-Jalalayn interprets "purifies it" as purging it of sins, and "instills it with corruption" as obscuring it with disobedience. Ibn Kathir clarifies that purification means obedience to Allah and cleansing from lowly characteristics, while corruption involves neglecting guidance and abandoning obedience.

The Prophet Muhammad ﷺ frequently supplicated for the purification of his soul. Zayd bin Arqam reported him saying, "O Allah! Give my soul its good and purify it, for You are the best to purify it. You are its Guardian and Master" Muslim 48:99. This highlights the importance of seeking divine assistance in this inner struggle. The concept of Iman (faith) is perfected when one loves and hates solely for the sake of Allah, as stated in a Hadith (Bukhari and Muslim, cited in Ma'arif-ul-Quran for 3:30).

Furthermore, the Quran provides practical guidance for guarding the soul against corruption. For instance, in the story of Prophet Yusuf, his flight from temptation demonstrates the need to abandon situations that lead to sin, as Ma'arif-ul-Quran notes for And they raced to the door. The guidance also extends to social interactions, emphasizing treating all people with kindness and justice while maintaining appropriate boundaries in friendship, especially with disbelievers who oppose the faith. As explained by Ma'arif-ul-Quran for “0. those who believe, do not take My enemy and your enemy as friends”, emotional, intimate friendship (Muwalat) is reserved for true Muslims, while benevolence (Muwasat) and customary cordiality (Mudarat) are permissible with non-belligerent non-Muslims.

The balance between divine decree and human free will is a nuanced aspect of the soul's existence. While Allah has preordained certain aspects of human destiny, such as one's ultimate abode Bukhari 23:115, humans are still commanded to strive for righteousness. As the Prophet Muhammad ﷺ said when asked about preordainment and actions, "Whoever Allah created for one of the two positions (Paradise or Hell), He makes it easy for him (to attain)" (Ahmad and Muslim, cited in Tafsir Ibn Kathir for 91:8). This implies that effort facilitates destiny, and one's actions are meaningful.

Allah's comprehensive knowledge of everything, even what the earth takes of them after death, reassures believers of His ability to resurrect all souls. Despite disbelievers' astonishment at the concept of resurrection, Allah reminds them of His infinite power demonstrated in creating the heavens and earth, which are greater than the creation of mankind (Tafsir Ibn Kathir 50:7). This understanding of Divine omnipotence underpins the certainty of the soul's resurrection and eventual judgment.

The concept of the Nafs in Islam is thus profoundly rich, encompassing its divine creation, inherent moral dualities, personal accountability, and its eternal journey. From its initial inspiration with discernment of right and wrong to its ultimate reckoning on the Day of Judgment, the soul's trajectory is guided by divine revelation and human striving. The pursuit of tazkiyat al-nafs (soul purification) is therefore not merely a spiritual exercise but a fundamental human responsibility, leading to success in this life and the Hereafter. The intricate interplay of divine mercy, human effort, and ultimate justice underscores the centrality of the Nafs in the Islamic worldview.