We are used as arrows

It is vain for you to rise up early, to sit up late, to eat the bread of sorrows: for so he giveth his beloved sleep. Lo, children are an heritage of the Lord: and the fruit of the womb is his reward. As arrows are in the hand of a mighty man; so are children of the youth. Happy is the man that hath his quiver full of them: they shall not be ashamed, but they shall speak with the enemies in the gate. (Psalm 127:2-5 KJV)