قَالَ النَّبِيُّ ص لَنْ يَعْمَلَ ابْنُ آدَمَ عَمَلًا أَعْظَمَ عِنْدَ اللَّهِ عَزَّ وَ جَلَّ مِنْ رَجُلٍ قَتَلَ نَبِيّاً أَوْ هَدَمَ الْكَعْبَةَ الَّتِي جَعَلَهَا اللَّهُ عَزَّ وَ جَلَّ قِبْلَةً لِعِبَادِهِ أَوْ أَفْرَغَ مَاءَهُ فِي امْرَأَةٍ حَرَاماً.
English translationBab Ul Qaim Publications
Hadith.4921 - The Prophet (peace be upon him and his family) said: "The son of Adam will not commit a deed greater in sin before Allah (swt), the Mighty and Majestic, than a man who kills a prophet, or demolishes the Kaaba which Allah (swt), has made as a Qibla for His (swt) servants, or discharges his semen unlawfully in a woman."
Translation: Bab Ul Qaim Publications·Thaqalayn link·The Arabic above is the original.