Riyad as-Salihin, Book 1, Hadith 87 (In-Book) ⓘ

Abu Hurairah (May Allah be pleased with him) reported: Messenger of Allah said, "Be prompt in doing good deeds (before you are overtaken) by turbulence which would be like a part of the dark night. A man would be a believer in the morning and turn to disbelief in the evening, or he would be a believer in the evening and turn disbeliever in the morning, and would sell his Faith for worldly goods."[Muslim].

فالأول‏:‏ عن أبي هريرة رضي الله عنه أن رسول الله صلى الله عليه وسلم قال‏:‏ ‏ "‏ بادروا بالأعمال فتناً كقطع الليل المظلم يصبح الرجل مؤمنا ويمسي كافراً ويمسي مؤمنا ويصبح كافراً، يبيع دينه بعرض من الدنيا‏" ‏ ‏(‏‏(‏رواه مسلم‏)‏‏)‏‏.‏