Musannaf Ibn Abi Shayba 13:3299

Abu Bakr narrated to us, he said: Ibn 'Uyaynah narrated to us, from 'Amr, from Muhammad ibn 'Ali, he said: The charity of the Prophet, may Allah bless him and grant him peace, was written to me. So I came to Mahmud ibn Labid and asked him. He said: "Indeed, 'Umar had an orphan with him, and he sold his property for three years."