Mukhtasar Muslim

It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: Whoever buys grain should not sell it until he has taken possession of it. Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: I consider this to apply to everything.

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that he said to Marwan bin Al-Hakam (the governor of Madinah): "Have you made the sale of usury lawful?" Marwan said: "Why, what have I done?" Sayyiduna Abu Hurairah (may Allah be pleased with him) said: "You have permitted the sale of receipts, whereas the Messenger of Allah (peace and blessings be upon him) forbade the sale of grain until it is taken into possession." Then Marwan addressed the people and forbade them from selling receipts. (The narrator of the hadith) Sulaiman says: "I saw the guards snatching those receipts from the people."