'Abdullah reported Allah's Messenger (ﷺ) as saying; I shall be there at the Cistern before you, and I shall have to contend for some people, but I shall have to yield. I would be saying: My Lord, they are my friends, they are my friends, and it would be said: You don't know what innovations they made after you.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَأَبُو كُرَيْبٍ وَابْنُ نُمَيْرٍ قَالُوا حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ شَقِيقٍ، عَنْ عَبْدِ اللَّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَنَا فَرَطُكُمْ عَلَى الْحَوْضِ وَلأُنَازِعَنَّ أَقْوَامًا ثُمَّ لأُغْلَبَنَّ عَلَيْهِمْ فَأَقُولُ يَا رَبِّ أَصْحَابِي أَصْحَابِي . فَيُقَالُ إِنَّكَ لاَ تَدْرِي مَا أَحْدَثُوا بَعْدَكَ " .
sunnah.com