According to search-discovered classical Islamic scholarship, Hasad (حسد) is the destructive spiritual disease of envy, defined as the state of wishing for a blessing, talent, or merit possessed by another person to be removed from them. Imam Al-Ghazali and Ibn al-Qayyim explain that this is not merely wanting a similar blessing for oneself—which can be a permissible form of competition called Ghibtah—but a malicious desire that stems from discontent with Allah's divine decree (Qadr). The Quran directly addresses the root of this sin in Surah An-Nisa (4:32), forbidding believers from coveting the bounties Allah has granted to others, thereby instructing them to purify their inner state. Furthermore, in Surah Al-Falaq (113:5), believers are commanded to seek refuge in Allah from the tangible harm an envier can cause when they act on their envy. This synthesis, supported by numerous Prophetic traditions, establishes Hasad as a major sin (haram) that consumes good deeds, corrupts faith, and leads to a host of other vices, making its cure essential for spiritual development.