Musannaf Ibn Abi Shayba 34:190

Zayd ibn al-Hubab narrated to us, from Mu'awiyah ibn Salih, who said: Abu Ayyub and Abu Zayd al-Homsi narrated to me, from 'Ubadah ibn al-Walid ibn 'Ubadah, from his father, that he entered upon 'Ubadah while he was ill. He said: I heard the Messenger of Allah, may Allah bless him and grant him peace, saying: "The first thing Allah created was the Pen. He said: 'Write.' So it wrote at that very hour what is to be."