"I said: 'O Messenger of Allah, which sin is the most grievous?' He said: 'Setting up a rival to Allah while it is He that has created you.' I said: 'Then what?' He said: 'Killing your child for fear that he may eat with you.' I said: 'Then what?' He said: 'Committing adultery with your neighbor's wife.'" (Using translation from Nasāʾī 4013)
قُلْتُ يَا رَسُولَ اللهِ أَيُّ الذَّنْبِ أَعْظَمُ؟ قَالَ «أَنْ تَجْعَلَ لِلَّهِ نِدًّا وَهُوَ خَلَقَكَ» قُلْتُ ثُمَّ مَاذَا؟ قَالَ «أَنْ تَقْتُلَ وَلَدًا خَشْيَةَ أَنْ يَعْنِي يَطْعَمَ مَعَكَ» قُلْتُ ثُمَّ مَاذَا؟ قَالَ «أَنْ تُزَانِيَ بِحَلِيلَةِ جَارِكَ»