Sahih al-Bukhari 52:15
Narrated Zahdam bin Mudrab:
I heard `Imran bin Husain saying, "The Prophet (ﷺ) said, 'The best people are those living in my generation, then those coming after them, and then those coming after (the second generation)." `Imran said "I do not know whether the Prophet (ﷺ) mentioned two or three generations after your present generation. The Prophet (ﷺ) added, 'There will be some people after you, who will be dishonest and will not be trustworthy and will give witness (evidences) without being asked to give witness, and will vow but will not fulfill their vows, and obesity will appear among them."
Reference
Sahih al-Bukhari 52:15
In-book reference
Book 52, Hadith 15
Arabic Text
حَدَّثَنَا آدَمُ، حَدَّثَنَا شُعْبَةُ، حَدَّثَنَا أَبُو جَمْرَةَ، قَالَ سَمِعْتُ زَهْدَمَ بْنَ مُضَرِّبٍ، قَالَ سَمِعْتُ عِمْرَانَ بْنَ حُصَيْنٍ ـ رضى الله عنهما ـ قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم " خَيْرُكُمْ قَرْنِي، ثُمَّ الَّذِينَ يَلُونَهُمْ، ثُمَّ الَّذِينَ يَلُونَهُمْ ". قَالَ عِمْرَانُ لاَ أَدْرِي أَذَكَرَ النَّبِيُّ صلى الله عليه وسلم بَعْدُ قَرْنَيْنِ أَوْ ثَلاَثَةً. قَالَ النَّبِيُّ صلى الله عليه وسلم " إِنَّ بَعْدَكُمْ قَوْمًا يَخُونُونَ وَلاَ يُؤْتَمَنُونَ، وَيَشْهَدُونَ، وَلاَ يُسْتَشْهَدُونَ وَيَنْذِرُونَ وَلاَ يَفُونَ، وَيَظْهَرُ فِيهِمُ السِّمَنُ ".