"I said: 'O Messenger of Allah, which sin is most grievous?' He said: 'Setting up a rival to Allah while it is He that created you.' I said: 'Then what?' He said: 'Killing your child so that he will not eat with you.' I said: 'Then what?' He said: 'Committing adultery with your neighbor's wife.'" (Using translation from Nasāʾī 4014)
قُلْتُ يَا رَسُولَ اللهِ أَيُّ الذَّنْبِ أَعْظَمُ؟ قَالَ «أَنْ تَجْعَلَ لِلَّهِ نِدًّا وَهُوَ خَلَقَكَ» قُلْتُ ثُمَّ أَيُّ؟ قَالَ «ثُمَّ أَنْ تَقْتُلَ وَلَدَكَ مِنْ أَجْلِ أَنْ يَطْعَمَ مَعَكَ» قُلْتُ ثُمَّ مَاذَا؟ قَالَ «ثُمَّ أَنْ تُزَانِيَ حَلِيلَةَ جَارِكَ»