Abdullah bin Masud reported,
I asked the Prophet ﷺ, "Which sin is greatest in the sight of Allah?"He replied, "That you set up a rival to Allah, when it is He who created you."I said, "That is indeed a grave sin." Then I asked, "Which is next?"He said, "That you kill your child for fear that he will eat with you."I asked, "Then which?"He answered, "That you commit adultery with your neighbor's wife."
Azami 227
Sahihعن عبد الله بن مسعود، قال
سألت النبي ﷺ: أي الذنب أعظم عند الله؟ قال: أن تجعل الله ندا وهو خلقك قلت: إن ذلك لعظيم قلت: ثم أي؟ قال: وأن تقتل ولدك تخاف أن يطعم معك قلت: ثم أي؟ قال: أن تزاني حليلة جارك.
Bukhari related it in the Tafsir (4477), and Muslim in the Iman (86), both from Uthman bin Abu Shayba, who said, Jareer narrated to us, from Mansur, from Abu Waail, from Amr bin Shurahbil, from Abdullah, and he mentioned it, and their wording is the same. The two sheikhs also related it, Bukhari (4761, 6001, 6861, 7532), and Muslim, both through routes from Jareer, with the same content, and he added at the end of the hadith, "Then Allah revealed, confirming it, "And those who do not invoke another god besides Allah, nor kill the soul which Allah has forbidden except by right, nor commit fornication. And whoever does that will meet a penalty" [Furqan 25:68]."