Narrated `Abdur-Rahman bin Abu Bakra: that his father said, "The Prophet forbade the selling of gold for gold and silver for silver except if they are equivalent in weight, and allowed us to sell gold for silver and vice versa as we wished."
Hadith ReferenceSahih Bukhari / The Book of Sales (Bargains) / Hadith: 2182
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة