It his been narrated on the authority of Umair b. Umm Hani who said: I heard Mu'awiya say (while delivering a sermon from the pulpit) that he heard the Messenger of Allah (ﷺ) say: A group of people from my Umma will continue to obey Allah's Command, and those who desert or oppose them shall not be able to do them any harm. They will be dominating the peeple until Allah's Command is executed (i. e. Resurrection is established).
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مَنْصُورُ بْنُ أَبِي مُزَاحِمٍ، حَدَّثَنَا يَحْيَى بْنُ حَمْزَةَ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ يَزِيدَ، بْنِ جَابِرٍ أَنَّ عُمَيْرَ بْنَ هَانِئٍ، حَدَّثَهُ قَالَ سَمِعْتُ مُعَاوِيَةَ، عَلَى الْمِنْبَرِ يَقُولُ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " لاَ تَزَالُ طَائِفَةٌ مِنْ أُمَّتِي قَائِمَةً بِأَمْرِ اللَّهِ لاَ يَضُرُّهُمْ مَنْ خَذَلَهُمْ أَوْ خَالَفَهُمْ حَتَّى يَأْتِيَ أَمْرُ اللَّهِ وَهُمْ ظَاهِرُونَ عَلَى النَّاسِ " .
sunnah.com