Musnad Ahmad 32:1574

Abu Salamah al-Khuza'i narrated to us, Malik informed us, from al-Zuhri ibn Shihab, from Anas ibn Malik, that the Prophet, peace and blessings of Allah be upon him, entered on the day of the Conquest while wearing a helmet. He said: It was said to him, "Ibn Khatal is clinging to the curtains of the Ka'bah." He said, "Kill him."