Musnad Ahmad 33:992

Rawh narrated to us, Ibn Jurayj narrated to us, Abu al-Zubayr informed me that he heard Jabir ibn Abdullah saying: "The Prophet, peace and blessings of Allah be upon him, commanded Umar ibn al-Khattab on the day of the Conquest, while he was at al-Batha, to go to the Kaaba and erase every image in it." And he did not enter the House until every image in it had been erased.