Musnad Ahmad 28:87

Hashim ibn al-Qasim narrated to us, Layth narrated to us, Abu Qabil al-Ma'afiri narrated to me, from Shufayy al-Asbahi, from Abdullah ibn Amr, from the Messenger of Allah (peace and blessings of Allah be upon him), who said: The Messenger of Allah (peace and blessings of Allah be upon him) came out to us, and in his hand were two books. He said: "Do you know what these two books are?" We said: "No, unless you inform us, O Messenger of Allah." He said to the one in his right hand: "This is a book from the Lord of the Worlds, Blessed and Exalted is He, containing the names of the people of Paradise, and the names of their fathers and their tribes. Then it is summarized at the end of them; nothing will be added to them, nor will anything be subtracted from them, ever." Then he said to the one in his left hand: "This is the book of the people of the Fire, with their names and the names of their fathers and their tribes. Then it is summarized at the end of them; nothing will be added to them, nor will anything be subtracted from them, ever." The companions of the Messenger of Allah (peace and blessings of Allah be upon him) said: "For what purpose, then, should we act if this is a matter that has already been finished?" The Messenger of Allah (peace and blessings of Allah be upon him) said: "Be upright and draw near, for the person of Paradise will have his end sealed with the deeds of the people of Paradise, no matter what deeds he performed. And the person of the Fire will have his end sealed with the deeds of the people of the Fire, no matter what deeds he performed." Then he said, closing his hand, and said: "Your Lord, Mighty and Majestic is He, has finished with the servants." Then he gestured with his right hand and cast it, saying: "A group in Paradise." And he cast with his left, saying: "A group in the Blaze."