We were with Fadala bin Ubayd on a military expedition when a necklace containing gold, silver, and gems came into the share of myself and my companions. I wanted to purchase it, so I asked Fadala bin Ubayd about it.He said, "Remove its gold and place it on one side of a scale, and place your own gold on the other side. Then do not take anything except equal weight for equal weight, for I heard the Messenger of Allah ﷺ say, 'Whoever believes in Allah and the Last Day must not take anything except equal weight for equal weight.'"
كنا مع فضالة بن عبيد في غزوة، فطارت لي ولأصحابي قلادة فيها ذهب وورق وجوهر، فأردت أن أشتريها، فسألت فضالة بن عبيد، فقال: انزع ذهبها، فاجعله في كفة، واجعل ذهبك في كفة، ثم لا تأخذن إلا مثلا بمثل؛ فإني سمعت رسول الله ﷺ يقول: من كان يؤمن بالله واليوم الآخر فلا يأخذن إلا مثلا بمثل.
Muslim narrated it in the Book of Musaqah (1591: 92) from Abu Tahir, who said, Ibn Wahb informed us, from Qurrah bin Abdul-Rahman Muafiri and Amr bin Harith and others, that Amir bin Yahya Muafiri informed them from Hanash, who said, and then he mentioned it.Tirmidhi said, "The practice regarding this," Tirmidhi said, "The practice regarding this, according to some scholars among the companions of the Prophet ﷺ and others, is that they did not consider it permissible to sell a sword adorned with gold or silver, or a belt plated with silver, or anything similar, for dirhams, until it is separated and distinguished from it. This is the view of Ibn Mubarak, Shafii, Ahmad, and Ishaq. Some scholars among the companions of the Prophet ﷺ and others permitted this." End of quote.