Commentary
The word: فِتْيَةٌ(fityah) in: إِنَّهُمْ فِتْيَةٌ (They were young men - 13) is the plural of: فَتٰی (fata) which means someone young. According to Tafsir scholars, this word indicates that the time ripe for correction of deeds and morals, and the inculcation of guidance and righteousness, is invariably the time when one is young. When old, formerly acquired deeds and morals become so deeply rooted that - no matter how evident becomes the truth against these - it is very difficult to break loose from their shackles. Those among the noble Companions who responded to and believed in the call of the Holy Prophet ﷺ were, after all, mostly young people. (Ibn Kathir, Abu Hayyan)