Sayyiduna Fadalah bin Ubayd (may Allah be pleased with him) said: In the year of Khaybar, a necklace was brought to the Messenger of Allah (peace and blessings be upon him) in which beads were set with gold. A man had bought that necklace for seven or nine dinars. The Prophet (peace and blessings be upon him) said: "No, not until the two are separated." He said: I only intended the stones. He (peace and blessings be upon him) said: "No, not until the two are separated." The narrator said: So he returned it until they were separated.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10552