Riyad as-Salihin 87
Abu Hurairah (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) 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)‏‏)‏‏.‏