Sayyiduna Anas (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) intended to write a letter to the non-Arab (rulers), so people informed him: They only read a letter that has a seal with an inscription on it. So, under the command of the Prophet Muhammad (peace and blessings be upon him), a silver ring was made. On it was inscribed: "Muhammad, Messenger of Allah."