Abu Dawud Book 29, Hadith Number 4211.

Chapter : Signetring of iron.

Narated By Buraydah ibn al-Hasib : A man came to the Prophet (PBUH) and he was wearing a signet-ring of yellow copper. He said to him: How is it that I notice the odour of idols in you? So he threw it away, and came wearing an iron signet ring. He (the Prophet) said: What is it that I see you wearing the adornment of the inhabitants of Hell? So he threw it away. He asked: Apostle of Allah, what material I must use? He said: Make it of silver, but do not weigh it as much as a mithqal.

The narrator Muhammad did not say: “‘Abd Allah b. Muslim,” and al-Hasan did not say: “al-Sulaimi al-Marwazi.”