Musnad Ahmad 907:127

Abdullah narrated to us, Muhammad narrated to me, Amr narrated to us, Asbat narrated to us, from Simak, from Jabir ibn Samurah, from the one who narrated to him, from the Messenger of Allah, may Allah bless him and grant him peace, that he said: "This religion will continue to stand, a group of Muslims will fight for it until the Hour is established."