Bulugh al-Maram, Book 14, Hadith 19 (In-Book)

Narrated 'Imran bin Husain (RA): Allah's Messenger said: "Verily! The best of you (i.e. Muslims) are my generation, then their immediate followers, then their immediate followers. After them there will be people who will give (false) testimony without being asked (to testify), who will be treacherous and are not to be trusted, who will make vows and will not fulfill them, among whom obesity will appear." [Agreed upon].

وَعَنْ عِمْرَانَ بْنِ حُصَيْنٍ ‏- رضى الله عنه ‏- قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ "إِنَّ خَيْرَكُمْ قَرْنِي, ثُمَّ اَلَّذِينَ يَلُونَهُمْ, ثُمَّ اَلَّذِينَ يَلُونَهُمْ, ثُمَّ يَكُونُ قَوْمٌ يَشْهَدُونَ وَلَا يُسْتَشْهَدُونَ, وَيَخُونُونَ وَلَا يُؤْتَمَنُونَ, وَيَنْذُرُونَ وَلَا يُوفُونَ, وَيَظْهَرُ فِيهِمْ اَلسِّمَنُ" } مُتَّفَقٌ عَلَيْه ِ 1‏.‏ ‏1 ‏- صحيح.‏ رواه البخاري ( 2651 )‏، ومسلم ( 2535 )‏.‏

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also referenced under: Book 14, Hadith 1415 (English)