Musannaf Ibn Abi Shaybah

Hazrat Anas narrates from the Prophet (peace and blessings be upon him) that he said: Before the Day of Judgment, there will be tribulations like pieces of a dark night. A person will be a believer in the morning and become a disbeliever by evening, and will be a disbeliever in the morning and become a Muslim by evening. Some people will sell their religion for worldly goods.