كتاب الإيمان
1  
The Book of Faith
(71)
Chapter: The descent of 'Eisa bin Mariam to judge according to the Shari'ah of our Prophet Muhammad (saws); And how Allah has honored this Ummah; And clarifying the evidence that this religion will not be abrogated; and that a group from it will continue to adhere to the truth and prevail until the day of resurrection
(71)
باب نُزُولِ عِيسَى ابْنِ مَرْيَمَ حَاكِمًا بِشَرِيعَةِ نَبِيِّنَا مُحَمَّدٍ صلى الله عليه وسلم
Sahih Muslim 155 e

It is narrated on the authority of Abu Huraira that he heard the Messenger of Allah (ﷺ) as saying:

What would you do when the son of Mary would descend and lead you?
وَحَدَّثَنِي مُحَمَّدُ بْنُ حَاتِمٍ، حَدَّثَنَا يَعْقُوبُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا ابْنُ أَخِي ابْنِ شِهَابٍ، عَنْ عَمِّهِ، قَالَ أَخْبَرَنِي نَافِعٌ، مَوْلَى أَبِي قَتَادَةَ الأَنْصَارِيِّ أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ، يَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ كَيْفَ أَنْتُمْ إِذَا نَزَلَ ابْنُ مَرْيَمَ فِيكُمْ وَأَمَّكُمْ ‏"‏ ‏.‏
Reference : Sahih Muslim 155 e
In-book reference : Book 1, Hadith 300
USC-MSA web (English) reference : Book 1, Hadith 291
  (deprecated numbering scheme)