Musnad Ahmad 30:1488

Hassan narrated to us, Ibn Lahi'ah narrated to us, Abu Yunus narrated to us, from Abu Hurairah, from the Messenger of Allah (peace and blessings of Allah be upon him), that he said: "By the One in whose hand is the soul of Muhammad, there is no one of this nation—a Jew or a Christian—who hears of me, then dies and does not believe in that which I was sent with, except that he will be among the companions of the Fire."