Abu Dawud Book 16, Hadith Number 3353.

Chapter : Not known.

Narated By Sa’d ibn AbuWaqqas : Zayd AbuAyyash asked Sa’d ibn AbuWaqqas about the sale of the soft and white kind of wheat for barley. Sa’d said: Which of them is better? He replied: Soft and white kind of wheat. So he forbade him from it and said: I heard the Apostle of Allah (PBUH) say, when he was asked about buying dry dates for fresh. The Apostle of Allah (PBUH) said: Are fresh dates diminished when they become dry? The (the people) replied: Yes. So the Apostle of Allah (PBUH) forbade that.