Al-Matalib al-'Aliyah 1370 — Usury (riba)

Ishaq narrated, through the chain of Abu Amir al-Aqadi, from Abu Qays: "Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) wrote to the commanders of the armies in Syria: You have descended into a land where usury (riba) is widespread, so do not sell gold for gold except exactly equal in weight, nor silver for silver except exactly equal in weight, nor food grain for food grain except exactly equal in measure."
I (Ibn Hajar) say: Muhammad bin al-Sa'ib is in fact Ibn al-Kalbi, who is completely matruk (abandoned). Imam Ishaq narrated his hadith because it has a basis, and he cited as supporting evidence the mawquf narration mentioned after it. He also said that there is no harm in its chain. I think that Abu Qays is the freed slave of Sayyiduna Amr bin al-As (may Allah be pleased with him), from whom Ali bin Rabah heard. And I do not know whether he heard this directly from Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) or read it in his letter.