Musnad Ahmad 32:1492

Abu Ahmad al-Zubayri narrated to us, Malik narrated to us, from Ibn Shihab, that Anas ibn Malik informed him that the Messenger of Allah (peace and blessings of Allah be upon him) entered Makkah while upon his head was a helmet. It was said to him: "Indeed, Ibn Khatal is clinging to the curtains of the Kaaba." He said: "Kill him."