כְּחִצִּ֥ים בְּיַד־גִּבּ֑וֹר כֵּ֝֗ן בְּנֵ֣י הַנְּעוּרִֽים׃
Как стрелы в руке сильного человека, так и дети юности.
Rashi on Psalms
Like arrows in the hand of a mighty man with which to battle his enemies.
Rashi on Psalms
so are the sons of one’s youth The disciples that a man sets up in his youth.