A song of ascents. Of Solomon.

1 Unless the LORD builds the house, the builders labor in vain. Unless the LORD watches over the city, the guards stand watch in vain.

Read Psalm 127:1 Using Other Translations

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.
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.
Unless the LORD builds a house, the work of the builders is wasted. Unless the LORD protects a city, guarding it with sentries will do no good.