Musnad Ahmad 30:3399

Yazid narrated to us, Muhammad informed us, from Abu Salamah, from Abu Hurairah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "We are the last, the first on the Day of Resurrection, except that they were given the Book before us, and we were given it after them. This is their day which was ordained for them, but they differed concerning it, so Allah guided us to it. The people are followers of us in it: today is for us, tomorrow is for the Jews, and the day after tomorrow is for the Christians."