Musannaf Ibn Abi Shayba 13:3261

Abu Bakr narrated to us, he said: Muhammad ibn Bishr narrated to us, he said: Muhammad ibn Muslim narrated to us, from Ibn Abi Najih, from Mujahid, who said: It is not appropriate that one sells on credit and buys with it, nor that one sells for cash and buys on credit. And there is no harm in selling on credit and buying with cash.