Sunan an-Nasa'i 5217

It was narrated from Ibn 'Umar that:The Messenger of Allah [SAW] wore a ring of gold for three days, and when his Companions saw it, gold rings became popular. Then he threw it away and we did not realize what he had done. Then he ordered that a ring of silver be made, and that (the words): "Muhammad Rasul Allah" be engraved on it. It remained on the hand of the Messenger of Allah [SAW] until he died, then on the hand of Abu Bakr until he died, then on the hand of 'Umar until he died. Then (it remained) on the hand of 'Uthman for the first six years of his duties, but when he had to write many letters, he gave it to a man from among Ansar who used to seal letters with it. Then the Ansari went out to a well belonging to 'Uthman and the ring fell. They looked for it but could not find it. He ordered that a similar ring be made and engraved (the words): "Muhammad Rasul Allah" on it.