Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) narrates: I asked, "O Messenger of Allah (peace and blessings be upon him)! Which sin is the greatest?" He replied, "That you associate a partner with Allah while He created you." I asked, "Then what?" He (peace and blessings be upon him) said, "That you kill your child out of fear that he will eat with you." I asked, "Then what?" He (peace and blessings be upon him) said, "That you commit adultery with your neighbor's wife." (The narrator states) So Allah Almighty revealed this verse to confirm the statement of the Prophet (peace and blessings be upon him): "And those who do not worship any other along with Allah, nor do they kill a soul which Allah has forbidden except by right, nor do they commit adultery."