Hadith.4977 - The Messenger of Allah (swt) (peace be upon him and his family) said: "The son of Adam will not commit a deed greater in sin before Allah (swt), the Almighty and Majestic, than a man who kills a prophet, or demolishes the Kaaba - which Allah (swt) has made a direction for His servants in prayer - or discharges his semen unlawfully into a forbidden woman."