A man said, "O Allah's Messenger (ﷺ)! Which sin is the greatest in Allah's Sight?" The Prophet (ﷺ) said, "To set up a rival unto Allah though He Alone created you . " The man said, "What is next?" The Prophet (ﷺ) said, "To kill your son lest he should share your food with you." The man said, "What is next?" The Prophet said, "To commit illegal sexual intercourse with the wife of your neighbor." So Allah revealed in confirmation of this narration:-- 'And those who invoke not with Allah, any other god. Nor kill, such life as Allah has forbidden except for just cause nor commit illegal sexual intercourse. And whoever does this shall receive the punishment.' (25.68)
Blood Money (Ad-Diyat) - Sahih al-Bukhari 6861
This narration from Sahih al-Bukhari presents a profound hierarchy of major sins as established by the Prophet Muhammad (ﷺ) himself, with Allah subsequently revealing Quranic verses confirming this teaching.
Commentary on the Greatest Sin: Shirk
The Prophet (ﷺ) identifies associating partners with Allah (shirk) as the gravest sin because it violates the fundamental purpose of creation - to worship Allah alone. This constitutes disbelief (kufr) and nullifies all good deeds.
Scholars explain that shirk represents the ultimate injustice, as it attributes divine qualities to created beings and denies Allah's exclusive right to worship. This sin is unforgivable if one dies upon it without repentance.
Commentary on Killing One's Child
The second gravest sin mentioned is killing one's child out of fear of poverty. Classical commentators emphasize this prohibition includes all unlawful killing, particularly highlighting the special sanctity of one's own offspring.
This sin combines multiple transgressions: violating the right to life, betraying parental trust, and displaying lack of trust in Allah's provision. Scholars note this was particularly relevant in pre-Islamic Arabia where female infanticide was practiced.
Commentary on Adultery with Neighbor's Wife
The third major sin specified is adultery with a neighbor's wife. Scholars explain this carries additional gravity due to multiple violations: illicit sexual relations, betrayal of community trust, and destruction of family structures.
The specification of "neighbor's wife" indicates the compounded sin of violating neighborhood rights (huqooq al-jiwaar), which Islam strongly emphasizes. This sin undermines social harmony and family integrity.
Quranic Confirmation and Scholarly Insights
The subsequent revelation of Surah Al-Furqan (25:68) confirms these prohibitions, demonstrating how Quranic revelation often validated and elaborated upon the Prophet's teachings.
Classical scholars note this hierarchy teaches us about the relative gravity of sins: theological crimes (shirk) are most severe, followed by crimes against life, then crimes against family and social order. The exception "except for just cause" in the verse refers to lawful execution or killing in legitimate warfare.