I asked the Prophet, "What is the greatest sin in the Sight of Allah?" He said, "That you set up a rival unto Allah though He Alone created you." I said, "That is indeed a great sin." Then asked, "What is next?" He said, "To kill your son lest he should share your food with you." I asked, "What is next?" He said, "To commit illegal sexual intercourse with the wife of your neighbor."
سَأَلْتُ النَّبِيَّ ﷺ: أَىُّ الذَّنْبِ أَعْظَمُ عِنْدَ اللَّهِ؟ قَالَ: «أَنْ تَجْعَلَ لِلَّهِ نِدًّا وَهْوَ خَلَقَكَ۔» قُلْتُ: إِنَّ ذَلِكَ لَعَظِيمٌ! قُلْتُ: ثُمَّ أَىُّ؟ قَالَ: «وَأَنْ تَقْتُلَ وَلَدَكَ تَخَافُ أَنْ يَطْعَمَ مَعَكَ۔» قُلْتُ: ثُمَّ أَىُّ؟ قَالَ: «أَنْ تُزَانِيَ حَلِيلَةَ جَارِكَ۔»