Sayyiduna Abu Sa'id (may Allah be pleased with him) narrated that the Messenger of Allah (peace and blessings be upon him) said: "When you make a salaf (advance-payment) sale in something, do not transfer it to something else." In one narration the wording is: "Whoever makes a salaf sale in something should not transfer it to something else."
Reliance is placed on the hadith in which selling wheat before taking it into one's possession is forbidden, because Atiyyah al-Awfi is not taken as proof.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 11153
Muhammad bin Zayd bin Khulaydah said: I asked Sayyiduna Ibn Umar (may Allah be pleased with them both) about the salaf sale. I said to him: We make salaf sales and say: If you give us wheat, we will take it at such-and-such a rate, and if you give us dates, at such-and-such a rate. He replied: Make a salam sale in each kind of commodity for a known amount of silver. If he gives it to you, (well and good); otherwise take back your capital, and do not sell it in exchange for other goods.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 11154
Sayyiduna Abu Hurayrah (may Allah be pleased with him) said: I went to Marwan bin al-Hakam in Madinah. Marwan had declared lawful the sale of sukuk (official vouchers), which have a fixed term, before they were taken into full possession. Sayyiduna Abu Hurayrah (may Allah be pleased with him) said: I said to him: You have made usury (riba) lawful, for wheat is being sold when it has not yet been taken into possession. And I bear witness that I heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever buys wheat should not sell it before measuring it out in full." So Marwan put a stop to that sale.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 11155
Sulayman bin Yasar (may Allah have mercy on him) said that Sayyiduna Abu Hurayrah (may Allah be pleased with him) said to Marwan: You have made bay' al-sukuk (the sale of vouchers) lawful, whereas the Messenger of Allah (peace and blessings be upon him) "forbade selling wheat before it has been measured out." He said: Then Marwan delivered a sermon and forbade that sale. Sulayman bin Yasar (may Allah have mercy on him) said: I saw the guards snatching them from people's hands.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 11156