Ibn ‘Abbas said :
Ubayy b. Ka’b told me that the Messenger of Allah ﷺ said : Al-khidr saw a youth playing with boys. He took him by his head and uprooted it. Moses then said : Hast thou slain an innocent person who had slain none.

حَدَّثَنَا مُحَمَّدُ بْنُ مِهْرَانَ الرَّازِيُّ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنْ عَمْرٍو، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، قَالَ قَالَ ابْنُ عَبَّاسٍ حَدَّثَنِي أُبَىُّ بْنُ كَعْبٍ، عَنْ رَسُولِ اللَّهِ ﷺ قَالَ " أَبْصَرَ الْخَضِرُ غُلاَمًا يَلْعَبُ مَعَ الصِّبْيَانِ فَتَنَاوَلَ رَأْسَهُ فَقَلَعَهُ فَقَالَ مُوسَى { أَقَتَلْتَ نَفْسًا زَكِيَّةً } " . الآيَةَ .