According to search-discovered classical Islamic scholarship, the concept of Evil (الشر, al-Shar) is not an independent force but a deviation from the divine good, originating from the misuse of free will by created beings. Ibn Kathir's tafsir on verses like 2:169 and 24:21 identifies Shaytan (Satan) as a primary external instigator who commands evil and indecency. Complementing this, scholars like Al-Ghazali, analyzing Quran 12:53, explain the internal source of evil as the Nafs al-Ammara—the lower self that persistently commands wrongdoing. The Quranic framework, particularly in verse 4:79, establishes clear human accountability, stating that any evil that befalls a person is from their own self. This synthesis across multiple verses and scholarly traditions frames evil not as a failure in divine power, but as a necessary consequence of free will, forming the basis of humanity's test and the eventual establishment of divine justice.