Musannaf Ibn Abi Shayba 22:322

Yahya ibn Adam narrated to us, he said: Qutbah ibn Abd al-Aziz narrated to us, from Asim, from Ikrimah, from Ibn Abbas, that he saw a Mushaf (copy of the Quran) being decorated. He said: "You are tempting the thieves with it; its adornment is within it."