Narrated AbdurRahman ibn AbuLayla: The Companions of the Prophet (ﷺ) told us that they were travelling with the Prophet (ﷺ). A man of them slept, and one of them went to the rope which he had with him. He took it, by which he was frightened. The Prophet (ﷺ) said: It is not lawful for a Muslim that he frightens a Muslim.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُحَمَّدُ بْنُ سُلَيْمَانَ الأَنْبَارِيُّ، حَدَّثَنَا ابْنُ نُمَيْرٍ، عَنِ الأَعْمَشِ، عَنْ عَبْدِ اللَّهِ بْنِ يَسَارٍ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي لَيْلَى، قَالَ حَدَّثَنَا أَصْحَابُ، مُحَمَّدٍ صلى الله عليه وسلم أَنَّهُمْ كَانُوا يَسِيرُونَ مَعَ النَّبِيِّ صلى الله عليه وسلم فَنَامَ رَجُلٌ مِنْهُمْ فَانْطَلَقَ بَعْضُهُمْ إِلَى حَبْلٍ مَعَهُ فَأَخَذَهُ فَفَزِعَ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لاَ يَحِلُّ لِمُسْلِمٍ أَنْ يُرَوِّعَ مُسْلِمًا " .
sunnah.com