Musnad Ahmad 2:51

'Affan narrated to us, Hammad narrated to us, 'Ammar ibn Abi 'Ammar informed us that 'Umar ibn al-Khattab said: The Messenger of Allah (ﷺ) saw a gold ring on a man's hand, so he said: "Cast this away." So he cast it away. Then he wore a ring of iron, so he said: "This is worse than it." Then he wore a ring of silver, so he remained silent regarding it.