Musannaf Ibn Abi Shayba 13:468

Abu Bakr narrated to us, he said: Ali bin Mushir and Ibn Abi Za’idah narrated to us, from Sadaqah bin al-Muthanna, from his grandfather, Riyah bin al-Harith, from Ammar bin Yasir, who said: One slave is better than two slaves, and one camel is better than two camels, and one garment is better than two garments. There is no harm in it if it is hand-to-hand. Riba (usury) is only in deferred payment (nasi’ah), except for what is measured and weighed.