Musannaf Ibn Abi Shayba 13:2253

Abu Bakr narrated to us, he said: Abd al-A’la narrated to us, from Hisham, from al-Hasan and Muhammad, that they both said regarding a man who borrowed a number of dirhams from a man in a land, and they were current by their weight: "Should he repay him by weight?" They disliked that, and they said: "He shall not repay him except with the like of his dirhams."