John Gill Commentary Nehemiah 6:16

"And it came to pass, when all our enemies heard [thereof], that all the nations that were about us feared, and were much cast down in their own eyes; for they perceived that this work was wrought of our God." — Nehemiah 6:16 (ASV)

And it came to pass, that when all our enemies heard thereof ,
&c.] That the wall was finished:

and all the Heathen that were about us saw these things ;
the neighbouring nations, who not only heard with their ears, but saw with their eyes what was done:

they were much cast down in their own eyes ;
through shame and confusion, because of their own scoffs and jeers; through grief and vexation at the unexpected success of the Jews, and through the fear of them that was fallen upon them, as Jarchi notes:

for they perceived that this work was wrought of our God ;
his special providence and blessing attending it, as appeared by its being so soon effected.