Charles Spurgeon, commenting on Psalm 127:1 :
Except the LORD build the house, they labour in vain that build it. The word vain is the keynote here, and we hear it ring out clearly three times. Men desiring to build know that they must labour, and accordingly they put forth all their skill and strength; but let them remember that if Jehovah is not with them their designs will prove failures. So was it with the Babel builders; they said, “Go to, let us build us a city and a tower”; and the Lord returned their words into their own bosoms, saying, “Go to, let us go down and there confound their language.” In vain they toiled, for the Lord’s face was against them. When Solomon resolved to build a house for the Lord, matters were very different, for all things united under God to aid him in his great undertaking: even the heathen were at his beck and call that he might erect a temple for the Lord his God. In the same manner God blessed him in the erection of his own palace; for this verse evidently refers to all sorts of house building. Without God we are nothing. Great houses have been erected by ambitious men; but like the baseless fabric of a vision they have passed away, and scarce a stone remains to tell where once they stood. The wealthy builder of a Non such Palace, could he revisit the glimpses of the moon, would be perplexed to find a relic of his former pride: he laboured in vain, for the place of his travail knows not a trace of his handiwork. The like may be said of the builders of castles and abbeys: when the mode of life indicated by these piles ceased to be endurable by the Lord, the massive walls of ancient architects crumbled into ruins, and their toil melted like the froth of vanity. Not only do we now spend our strength for nought without Jehovah, but all who have ever laboured apart from him come under the same sentence. Trowel and hammer, saw and plane are instruments of vanity unless the Lord be the Master builder.
Except the LORD keep the city, the watchman waketh but in vain. Around the wall the sentinels pace with constant step; but yet the city is betrayed unless the alert Watcher is with them. We are not safe because of watchmen if Jehovah refuses to watch over us. Even if the guards are wakeful, and do their duty, still the place may be surprised if God be not there. “I, the Lord, do keep it”, is better than an army of sleepless guards. Note that the Psalmist does not bid the builder cease from labouring, nor suggest that watchmen should neglect their duty, nor that men should show their trust in God by doing nothing: nay, he supposes that they will do all that they can do, and then he forbids their fixing their trust in what they have done, and assures them that all creature effort will be in vain unless the Creator puts forth his power, to render second causes effectual. Holy Scripture endorses the order of Cromwell—”Trust in God, and keep your powder dry”: only here the sense is varied, and we are told that the dried powder will not win the victory unless we trust in God. Happy is the man who hits the golden mean by so working as to believe in God, and so believing in God as to work without fear. In Scriptural phrase a dispensation or system is called a house. Moses was faithful as a servant over all his house; and as long as the Lord was with that house it stood and prospered; but when he left it, the builders of it became foolish and their labour was lost. They sought to maintain the walls of Judaism, but sought in vain: they watched around every ceremony and tradition, but their care was idle. Of every church, and every system of religious thought, this is equally true: unless the Lord is in it, and is honoured by it, the whole structure must sooner or later fall in hopeless ruin. Much can be done by man; he can both labour and watch; but without the Lord he has accomplished nothing, and his wakefulness has not warded off evil.