Ibn ‘Abbas said what the Prophet forbade was that grain should be sold before it had been received. Ibn ‘Abbas said, “I do not think this applies to every commodity, but only to things of that type.”
He reported God's Messenger as saying, “If anyone buys grain he must not sell it till he has received it in full.” A version by Ibn ‘Abbas has, ‘‘till he measures it out.”
Narrated Abu Huraira reported God's Messenger.as saying, “Do not go out to meet riders to conduct business with them; none of you must buy in opposition to one another1, nor must you bid against one another; a townsman must not sell for a man from the desert; and do not tie up the udders of camels and sheep,:
he may keep them if he is pleased with them, and may return them along with a sa‘ of dates if he is displeased with them.” A version by Muslim has, “If anyone buys a sheep whose udder has been tied up he has three days in which to decide whether to keep it or not; but if he returns it he must return with it a sa’ of any grain but wheat.”2
(Bukhari and Muslim.)
1. When agreement has obviously been reached, although the contract has not been confirmed, no one must step in and offer a higher price.
2. Samra’. The full pharse is hinta samra’, meaning "tawny wheat" ; then the adjective is used by itself as a word for wheat.
Ibn ‘Umar said they used to buy grain in the upper part of the market and sell it in the same spot, but God’s Messenger forbade them to sell it there before removing it.
Abu Dawud transmitted it. I have not found it in the two Sahihs.
