Sahih Muslim Book 10, Hadith Number 3893.

Chapter : Hoarding of foodstuff is forbidden.

Jabir b. ‘Abdullah (Allah be pleased with them) reported: Allah’s Messenger (may peace be upon him) bought a camel from me for two ‘uqiyas and a dirham or two dirhams. As he reached Sirar (a village near Medina), he commanded a cow to be slaughtered and it was slaughtered, and they ate of that, and as he (the Holy Prophet) reached Medina he ordered me to go to the mosque and offer two rak’ahs of prayer, and he measured for me the price of the camel and even made an excess payment to me.