Sahih Muslim Book 10, Hadith Number 3849.
Chapter : Sale of wheat like for like.
‘Uthman b. ‘Affan reported Allah’s Messenger (may peace be upon him) as saying: Do not sell a dinar for two dinars and one dirham for two dirhams.
‘Uthman b. ‘Affan reported Allah’s Messenger (may peace be upon him) as saying: Do not sell a dinar for two dinars and one dirham for two dirhams.