Ibn Hibban

Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said: "Whoever takes my letter to Caesar will be granted Paradise." One of those present asked: Even if I am not killed? The Prophet Muhammad (peace and blessings be upon him) said: Even if you are not killed (you will still be granted Paradise). So that person set out with the letter and reached Caesar when Caesar was in Bayt al-Maqdis, and a carpet had been spread for him. No one except Caesar would walk on that carpet. That person placed the letter on the carpet and stepped aside. When Caesar reached the letter, he took it and then called his trusted confidant and had him read the letter. He replied: I have the same knowledge about this letter as you do. Then Caesar said in a loud voice: Who is the person who brought this letter? He is granted protection. So that person came forward. Caesar said: When I come, come to me. When Caesar arrived, that person came to him. Caesar ordered his doors to be closed. Then he told the announcer to proclaim: Caesar has followed Muhammad (peace and blessings be upon him) and has abandoned Christianity. So his soldiers advanced, armed, and besieged his palace. Then Caesar said to the envoy of the Prophet Muhammad (peace and blessings be upon him): You have seen, I fear for my kingdom. Then he told the announcer to proclaim: Beware, Caesar is pleased with you; he only wanted to test you to see how firm you are in your religion. You may go back. So the people went back. Then Caesar wrote a letter to the Prophet Muhammad (peace and blessings be upon him) saying that he had become Muslim, and he also sent some dinars to the Prophet Muhammad (peace and blessings be upon him). When the Prophet Muhammad (peace and blessings be upon him) read his letter, he said: The enemy of Allah has lied; he is not a Muslim, he remains upon Christianity. The Prophet Muhammad (peace and blessings be upon him) distributed those dinars.