Yahya bin Qais says that I asked Ata about exchanging dinar for dinar and dirham for dirham when there is something extra between them, so he said that Ibn Abbas (may Allah be pleased with them) considers it permissible. Upon this, Abdullah bin Zubair (may Allah be pleased with him) said that Ibn Abbas is narrating something which he did not hear directly from the Prophet (peace be upon him). When Ibn Abbas (may Allah be pleased with them) came to know of this, he said: I did not hear this directly from the Prophet (peace be upon him), but Usama bin Zaid (may Allah be pleased with him) told me that the Prophet (peace be upon him) said: Riba (usury) is related to credit or delay.