Musnad Ahmad 26:5

Hashim narrated to us, Sayyar and Mughirah informed us, from Abu Wa'il, who said: Ibn Mas'ud said: Two traits—meaning one of them—I heard from the Messenger of Allah, peace and blessings of Allah be upon him, and the other is from myself: "Whoever dies while setting up a rival to Allah, enters the Fire." And I say: Whoever dies while not setting up a rival to Allah, and not associating anything with Him, enters Paradise.