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 Sahih Muslim 155 d

Arabic hadith text
حَدَّثَنِي حَرْمَلَةُ بْنُ يَحْيَى، أَخْبَرَنَا ابْنُ وَهْبٍ، أَخْبَرَنِي يُونُسُ، عَنِ ابْنِ شِهَابٍ، قَالَ أَخْبَرَنِي نَافِعٌ، مَوْلَى أَبِي قَتَادَةَ الأَنْصَارِيِّ أَنَّ أَبَا هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏كَيْفَ أَنْتُمْ إِذَا نَزَلَ ابْنُ مَرْيَمَ فِيكُمْ وَإِمَامُكُمْ مِنْكُمْ ‏"‏ ‏.‏
Translation
It is narrated on the authority of Abu Huraira that the Messenger of Allah (ﷺ) observed

What will be your state when the son of Mary descends amongst you and there will be an Imam amongst you?