صحيح البخاري

Narrated Jarir:

While I was at Yemen, I met two men from Yemen called Dhu Kala and Dhu `Amr, and I started telling them about Allah's Messenger. Dhu `Amr said to me, "If what you are saying about your friend (i.e. the Prophet) is true, then he has died three days ago." Then both of them accompanied me to Medina, and when we had covered some distance on the way to Medina, we saw some riders coming from Medina. We asked them and they said, "Allah's Messenger (ﷺ) has died and Abu Bakr has been appointed as the Caliph and the people are in a good state.' Then they said, "Tell your friend (Abu Bakr) that we have come (to visit him), and if Allah will, we will come again." So they both returned to Yemen. When I told Abu Bakr their statement, he said to me, "I wish you had brought them (to me)." Afterwards I met Dhu `Amr, and he said to me, "O Jarir! You have done a favor to me and I am going to tell you something, i.e. you, the nation of 'Arabs, will remain prosperous as long as you choose and appoint another chief whenever a former one is dead. But if authority is obtained by the power of the sword, then the rulers will become kings who will get angry, as kings get angry, and will be delighted as kings get delighted."