Psalm 127 A Song of Ascents. Of Solomon.

Unless the LORD builds the house, those who build it labor in vain. Unless the LORD watches over the city, the watchman stays awake in vain.
It is in vain that you rise up early and go late to rest, eating the bread of anxious toil; for he gives to his beloved sleep.
Behold, children are a heritage from the LORD, the fruit of the womb a reward.
Like arrows in the hand of a warrior are the children of one’s youth.
Blessed is the man who fills his quiver with them! He shall not be put to shame when he speaks with his enemies in the gate.

(ESV)