Abu Huraira reported: The Messenger of Allah, peace be upon him, said,

Abu Huraira reported: The Messenger of Allah, peace be upon him, said, “Hasten to perform good deeds before a tribulationwhich will be like the dark part of the night, in which a man will be a believer in the morning and an unbeliever in the evening, or he will be a believer in the evening and an unbeliever in the morning; and he would sell his faith for some goods in the world.”
[Sahih Muslim, Book 1, Number 213]

عَنْ أَبِي هُرَيْرَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ بَادِرُوا بِالْأَعْمَالِ فِتَنًا كَقِطَعِ اللَّيْلِ الْمُظْلِمِ يُصْبِحُ الرَّجُلُ مُؤْمِنًا وَيُمْسِي كَافِرًا أَوْ يُمْسِي مُؤْمِنًا وَيُصْبِحُ كَافِرًا يَبِيعُ دِينَهُ بِعَرَضٍ مِنْ الدُّنْيَا

118 صحيح مسلم كِتَاب الْإِيمَانِ باب الْحَثِّ عَلَى الْمُبَادَرَةِ بِالْأَعْمَالِ قَبْلَ تَظَاهُرِ الْفِتَنِ