Sahih Muslim Book 10, Hadith Number 3836.

Chapter : The sale of silver for gold is prohibited when payment is to be made in future.

‘Abd al-Rahman b. Wa’ala as-Saba’i (who was an Egyptian) asked ‘Abdullah b. Abbas; (Allah be pleased with them) about that which is extracted from the grapes, whereupon he said: A person presented to Allah’s Messenger (may peace be upon him) a small water-skin of wine. Allah’s Messenger (may peace be upon him) said to him: Do you know that Allah has forbidden it? He said: No. He then whisper- ed to another man. Allah’s Messenger (may peace be upon him) asked him what he had whispered. He said: I advised him to sell that, whereupon he (the Holy Prophet) said: Verily He Who has forbidden its drinking has forbidden its sale also. He (the narrator) said: He opened the water-skin until what was contained in it was spilt.