Language:
كتاب الفتن
92  
Afflictions and the End of the World
(2)
Chapter: “After me you will see things which you will disapprove of.”
(2)
باب قَوْلِ النَّبِيِّ صلى الله عليه وسلم ‏"‏ سَتَرَوْنَ بَعْدِي أُمُورًا تُنْكِرُونَهَا ‏"‏
Sahih al-Bukhari 7057

Narrated Usaid bin Hudair:

A man came to the Prophet (ﷺ) and said, "O Allah's Messenger (ﷺ)! You appointed such-and-such person and you did not appoint me?" The Prophet (ﷺ) said, "After me you will see rulers not giving you your right (but you should give them their right) and be patient till you meet me."

حَدَّثَنَا مُحَمَّدُ بْنُ عَرْعَرَةَ، حَدَّثَنَا شُعْبَةُ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، عَنْ أُسَيْدِ بْنِ حُضَيْرٍ، أَنَّ رَجُلاً، أَتَى النَّبِيَّ صلى الله عليه وسلم فَقَالَ يَا رَسُولَ اللَّهِ اسْتَعْمَلْتَ فُلاَنًا وَلَمْ تَسْتَعْمِلْنِي‏.‏ قَالَ ‏ "‏ إِنَّكُمْ سَتَرَوْنَ بَعْدِي أَثَرَةً، فَاصْبِرُوا حَتَّى تَلْقَوْنِي ‏"‏‏.‏
Reference : Sahih al-Bukhari 7057
In-book reference : Book 92, Hadith 9
USC-MSA web (English) reference : Vol. 9, Book 88, Hadith 179
  (deprecated numbering scheme)