Musannaf Ibn Abi Shayba 13:764

Abu Bakr narrated to us, he said: Yahya bin Abi Za'idah narrated to us, from [Ibn] Abi Ghaniyah, from Al-Hakam bin 'Utaybah, he said: One does not return to his companion regarding the *hawala* (transfer of debt) until he becomes bankrupt or dies, and he does not abandon it. For indeed, a man may be wealthy at one time and poor at another time.