Sahih Muslim
The Book of Transactions (Kitab Al-Buyu)
Book Number: 010 / Hadith Number: 3677
Abu Huraira (Allah be pleased with him) reported Allah's Messenger (may peace be upon him) as saying: Do not buy the fruit until their condition is clear, and do not buy the fresh dates. A hadith like this has been reported by Ibn 'Umar through another chain of transmitters.