Musannaf Ibn Abi Shayba 37:108

Yunus ibn Muhammad narrated to us, from Layth ibn Sa’d, from Yazid, from Abu Sinan, from Anas, from the Prophet (peace be upon him), who said: "Before the Hour, there will be tribulations like pieces of a dark night. A man will wake up as a believer and go to sleep as a disbeliever, and he will wake up as a disbeliever and go to sleep as a believer. And a people will sell their religion for a commodity of the worldly life."