Sayyidina Abdullah narrated: I asked Allah’s Messenger (ﷺ) “Which sin is the gravest”? He said, “That you set up rivals to Allah while He has created you, and that you kill your son lest he eats with you or from your food, and that you commit adultery with your neighbour’s wife.” He then recited these verses: And those who call not upon another god with Allah, and slay not the soul which Allah has forbidden, except by right, nor commit adultery, and he who does this shall meet the requital of sin-the chastisement shall be doubled for him on the Day of Resurrection, and he shall abide there in humiliated. -------------------------------------------------------------------------------- (25 : 68-69) [Bukhari 4761, Nisai 4019] --------------------------------------------------------------------------------