The word translated as frustrated
conveys the sense that the enemies’ plans had broken to bits, fallen apart. So these words are a confession of Judah’s dependence on the Lord. In the words of Psalm 127:1, unless the Lord watches over the city, the watchman stays awake in vain.
Nehemiah had prayed for God’s blessing (Nehemiah 4:9a) and then worked to protect the project (Nehemiah 4:9b, Nehemiah 4:13). God in mercy heard and answered. These words also recall the dismay the Lord had rained upon Israel’s enemies in the past (for example, Exodus 15:14–16; Exodus 23:27; Deuteronomy 2:25; Deuteronomy 7:23; Joshua 2:9–11). Jerusalem’s present crisis and the Lord’s gracious deliverance belong in the same category as the crises and deliverances of the past.
15 When our enemies heard that it was known to us and that God had frustrated their plan, we all returned to the wall, each to his work.