Salim narrates from his father (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) "forbade selling fruit before it ripens, and also forbade selling fruit for dried dates."
(b) Zayd bin Thabit (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) "granted a concession in the 'ariyyah sale."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10647