Mukhtasar Bukhari

Narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that he had the cup of the Prophet Muhammad (peace and blessings of Allah be upon him). He says that I gave water to the Messenger of Allah (peace and blessings of Allah be upon him) in this cup for a long time. (The narrator) says that there was an iron ring in this cup. Sayyiduna Anas (may Allah be pleased with him) wished to replace it with a silver or gold ring, but Sayyiduna Abu Talha (may Allah be pleased with him) said (upon hearing this), "Do not change what the Messenger of Allah (peace and blessings of Allah be upon him) has made." So Sayyiduna Anas (may Allah be pleased with him) left it as it was.