Sayyiduna Sa'd (may Allah be pleased with him) said: On the day of the Conquest of Makkah, the Prophet (peace and blessings be upon him) granted safety to all the people except four men and two women, about whom he said: "Kill them, even if they are clinging to the curtains of the Ka'bah."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب المرتد / 16862