Note: D J Estes, Like Arrows in the Hand of a Warrior (Psalm CXXVII), Vetus Testamentum, Vol. 41, (Jul., 1991), pp. 304-311, indicates that at least one author has suggested a chiastic structure, perhaps linking the house with children and the gates with the city.
A. 1 Except the LORD build the house,
they labour in vain that build it:
except the LORD keep the city,
the watchman waketh but in vain.
B.2 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.
B’. 3 Lo, children are an heritage of the LORD:
and the fruit of the womb is his reward.
A’. 4 As arrows are in the hand of a mighty man;
so are children of the youth.
5. 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.