مسند امام احمد بن حنبل · Hadith 5067

It was narrated from Abu Ishaaq, from a man from Najraan, that he asked Ibn 'Umar: I shall ask you only about two things: about raisins and dates, and about selling the crop of a palm tree for immediate payment before it is dearly ripe (salam transaction). Ibn 'Umar said: A drunken man was brought to the essenger of Allah and he said: I only drank a mixture of raisins and dates. He had him flogged as the hadd punishment, and he forbade mixing them. And a man brought the crop of another man's date palms in a salam transaction (in which payment was made immediately for something to be delivered later), then his palm tree did not bear any fruit that year, so the buyer wanted to take his money back but he did not give it to him. So he brought him to the Messenger of Adah (PBUH) who said. "Did his palm tree not bear fruit?" He said: No. He said: "Then why am you keeping his money?" So he gave it to him, and the Messenger of Allah (PBUH) forbade salam transactions with regard to dates until the fruit is fully ripe.