Mukhtasar Bukhari

Narrated Abdullah bin Mas'ud (may Allah be pleased with him): I asked the Prophet (peace and blessings of Allah be upon him), "Which sin is the greatest in the sight of Allah?" He said, "That you set up a partner with Allah while He created you." I said, "Indeed, that is a great sin." I asked, "Then which one after that?" He (peace be upon him) said, "That you kill your child out of fear that you will have to feed him." I asked, "Then which one after that?" He said, "That you commit adultery with your neighbor's wife."