Sahih Muslim | Book 10 | Hadith Number 3691

Narrated by Sahl b. Abu Hathma
Sahl b. Abu Hathma reported Allah's Messenger (may peace be upon him) having forbidden Muzabana, i.e. exchange of fresh dates with dry dates. except in case of those to whom donations of some trees have been made. It is for them that concession has been given.