Language:

Narrated `Abdullah:

The Prophet (ﷺ) said, "I am your predecessor at the Lake-Fount (Kauthar) and some men amongst you will be brought to me, and when I will try to hand them some water, they will be pulled away from me by force whereupon I will say, 'O Lord, my companions!' Then the Almighty will say, 'You do not know what they did after you left, they introduced new things into the religion after you.'"

حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ مُغِيرَةَ، عَنْ أَبِي وَائِلٍ، قَالَ قَالَ عَبْدُ اللَّهِ قَالَ النَّبِيُّ صلى الله عليه وسلم ‏ "‏ أَنَا فَرَطُكُمْ عَلَى الْحَوْضِ، لَيُرْفَعَنَّ إِلَىَّ رِجَالٌ مِنْكُمْ حَتَّى إِذَا أَهْوَيْتُ لأُنَاوِلَهُمُ اخْتُلِجُوا دُونِي فَأَقُولُ أَىْ رَبِّ أَصْحَابِي‏.‏ يَقُولُ لاَ تَدْرِي مَا أَحْدَثُوا بَعْدَكَ ‏"‏‏.‏
Reference : Sahih al-Bukhari 7049
In-book reference : Book 92, Hadith 2
USC-MSA web (English) reference : Vol. 9, Book 88, Hadith 173
  (deprecated numbering scheme)