Musnad Ahmad 283:3

Sufyan narrated to us, from Yahya ibn Sa'id, from Bashir ibn Yasar, from Sahl ibn Abi Hathma, who said: "The Messenger of Allah (may Allah bless him and grant him peace) forbade the selling of fruit for dates, and he granted a concession regarding *al-'araya* (the sale of fresh dates on the tree for dried dates of equivalent value), that they be bought by their estimation, so that their people may eat them fresh." Sufyan said: "Yahya ibn Sa'id said to me: 'And what do the people of Makkah know about *al-'araya*?' I said: 'Ata' informed them; he heard it from Jabir.'"