Musannaf Ibn Abi Shayba 13:1105

Abu Bakr narrated to us, he said: Muhammad ibn Abi ‘Adi narrated to us, from Salih ibn Abi al-Ahmar, from ‘Abbad ibn Sa‘id, that ‘Umar ibn ‘Abd al-‘Aziz said: Whoever sells a slave or a person under interdiction, then his wealth is [subject to] loss.