Ibn Ezra on Numbers 11:27

וירץ הנער. בה"א הוא הנודע לשרת משה חוץ מיהושע כי שרות יהושע איננו כשרות כל נער: AND THERE RAN A YOUNG MAN. The word na’ar (young man) has the definite article prefixed to it because it refers to the young man¹¹⁵Scripture does not identify the young man. who, aside from Joshua, was known to serve Moses. For Joshua’s service was not the usual service rendered by young men.¹¹⁶Joshua served Moses in more dignified tasks.