that Ubayy bin Ka'b narrated that the Prophet ﷺ said: "The boy that Al-Khidr killed was destined to be a disbeliever the day he was created.'" (Using translation from Tirmidhī 3150)
نَبِيُّ اللَّهِ ﷺ «إِنَّ الْغُلَامَ الَّذِي قَتَلَهُ الْخَضِرُ طُبِعَ يَوْمَ طُبِعَ كَافِرًا»
The young man whom Khadir killed was a non-believer by his very nature and had he survived he would have involved his parents in defiance and unbelief.
قَالَ رَسُولُ اللَّهِ ﷺ إِنَّ الْغُلاَمَ الَّذِي قَتَلَهُ الْخَضِرُ طُبِعَ كَافِرًا وَلَوْ عَاشَ لأَرْهَقَ أَبَوَيْهِ طُغْيَانًا وَكُفْرًا
that Ubayy bin Ka'b narrated that the Prophet ﷺ said: "The boy that Al-Khidr killed was destined to be a disbeliever the day he was created.'"
عَنِ النَّبِيِّ ﷺ قَالَ الْغُلاَمُ الَّذِي قَتَلَهُ الْخَضِرُ طُبِعَ يَوْمَ طُبِعَ كَافِرًا
that Ubayy bin Ka'b narrated that the Prophet ﷺ said: "The boy that Al-Khidr killed was destined to be a disbeliever the day he was created.'" (Using translation from Tirmidhī 3150)
عَنِ النَّبِيِّ ﷺ الْغُلَامُ الَّذِي قَتَلَهُ صَاحِبُ مُوسَى طُبِعَ يَوْمَ طُبِعَ كَافِرًا
"الْغُلام الَّذِي قَتَلَهُ الخَضِرُ طُبْعَ يَوْمَ طُبعَ كَافِرًا وَلَوْ عَاشَ لأَرْهَق أَبَوَيهِ طُغْيَانًا وكُفْرًا" .