Sunan Ibn Majah, Book 1, Hadith 179 (In-Book) ⓘ
It was narrated from Ibn 'Umar that: The Messenger of Allah said: "There will emerge people who will recite the Qur'an but it will not go any deeper than their collarbones. Whenever a group of them appears, they should be cut off (i.e. killed)." Ibn 'Umar said: "I heard the Messenger of Allah say: 'Whenever a group of them appears, they should be killed' - (he said it) more than twenty times- 'until Dajjal emerges among them.'"
حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا يَحْيَى بْنُ حَمْزَةَ، حَدَّثَنَا الأَوْزَاعِيُّ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ " يَنْشَأُ نَشْءٌ يَقْرَءُونَ الْقُرْآنَ لاَ يُجَاوِزُ تَرَاقِيَهُمْ كُلَّمَا خَرَجَ قَرْنٌ قُطِعَ " . قَالَ ابْنُ عُمَرَ سَمِعْتُ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ يَقُولُ " كُلَّمَا خَرَجَ قَرْنٌ قُطِعَ " . أَكْثَرَ مِنْ عِشْرِينَ مَرَّةً " حَتَّى يَخْرُجَ فِي عِرَاضِهِمُ الدَّجَّالُ " .
also referenced under: Hadith 174 (Reference) & Volume 1, Book 1, Hadith 174 (DarusSalam)