(47) باب بَيْعِ الذَّهَبِ بِالذَّهَبِ
It was narrated from Abu Saeed Al-Khudri that the Messenger of Allah said:
"Do not sell gold for gold except like for like and do not differentiate. Do not sell silver for silver except like for like, and do not sell it in return for something to be paid later."
Reference: Sunan an-Nasa'i 4570
In-book reference: Book 44, Hadith 122
English translation: Vol. 5, Book 44, Hadith 4574