In Psalm 127, children born in one's youth are compared to what?

Answer: Arrows in a warrior's hand

"Like arrows in the hand of a warrior, so are children born in one's youth. Blessed is the man whose quiver is full of them."

“Like arrows in the hand of a warrior, so are children born in one’s youth. Blessed is the man whose quiver is full of them. He will not be put to shame when he confronts the enemies at the gate.”— Psalm 127:4-5 (BSB)