Abu Hamzah Imran bin Abi Ata (may Allah have mercy on him) says: I said to Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both): My father is a dealer in goats and sheep, and he is in partnership with Jews and Christians. Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: We do not go into partnership with a Jew, a Christian or a Magian. I said: Why? (He said:) Because they take usury (riba), and usury is not permissible.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10822