Musnad Ahmad 30:1952

Yahya ibn Ishaq narrated to us, he said: Ibn Lahi'ah narrated to us, Abu Yunus narrated to us, from Abu Hurairah. And Hasan said: Ibn Lahi'ah narrated to us, he said: Abu Yunus narrated to us, from Abu Hurairah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Woe to the Arabs from an evil that has drawn near; tribulations like pieces of the dark night. A man will wake up as a believer and go to sleep as a disbeliever. A people will sell their religion for a small amount of worldly goods. The one who holds fast to his religion on that day is like one who holds onto burning coals—or he said: onto thorns." Hasan said in his narration: "The striking of thorns."