Hanash (may Allah have mercy on him) said: We were with Sayyiduna Fadalah bin Ubayd (may Allah be pleased with him) on a military campaign. Hanash (may Allah have mercy on him) said: There came to me and my companions necklaces containing gold, silver and gems. I wanted to buy them, so I asked Sayyiduna Fadalah bin Ubayd (may Allah be pleased with him) about it, and Fadalah (may Allah be pleased with him) said: Remove its gold and put it in one pan of the scale, and put your gold in the other pan, then take only equal for equal, for I heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever believes in Allah and the Last Day should take them only equal for equal."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10551