Mishkat al-Masabih 4396

Buraida reported the Prophet as saying to a man who was wearing a signet-ring of yellow copper, “How is it that I notice the odour of idols in you ?” So he threw it away and came wearing an iron signet- ring, and when he said, “How is it that I see you wearing the adornment of the inhabitants of hell ?” he threw it away and asked God’s messenger what material he should use. He replied, “Silver, but do not let it weigh as much as a mithqal.” Tirmidhi, Abu Dawud and Nasa’i transmitted it. Muhyi as-Sunna said there is a sound tradition on the authority of Sahl b. Sa'd about the dower that the Prophet said to a man, “Seek something, even though it should be an iron signet-ring.”