John Gill Commentary Nehemiah 4

But it came to pass, that when Sanballat heard that we
builded the wall
Or were building it; for as yet it was not finished, see (Nehemiah 4:6) ,

he was wroth, and took great indignation ;
inwardly, though outwardly he pretended to treat the work with contempt, as if it never would be accomplished, which yet he feared:

and mocked the Jews ;
as a set of foolish builders, and unable to finish what they had begun.

And he spoke before his brethren
Tobiah the Ammonite, and Geshem the Arabian, and perhaps some other governors of the king of Persia in those parts:

and before the army of Samaria :
which, and the inhabitants of it, were implacable enemies of the Jews:

and said, what do these feeble Jews ?
what do they pretend to do, or what can they do?

will they fortify themselves ?
by building a wall about their city; can they think they shall ever be able to do this, or that it will be allowed?

will they sacrifice ?
meaning not their daily sacrifice, as Jarchi, that they had done a long time, but for the dedication of their building, as Aben Ezra:

will they make an end in a day ?
they seem to be in as great a hurry and haste as if they meant it; and indeed, unless they can do it very quickly, they never will: they will soon be stopped:

will they revive the stones out of the heaps of the rubbish which are
burnt ?
where will they find materials? do they imagine that they can make burnt stones firm and strong again, or harden the dust and rubbish into stones, or make that, which is as if dead, alive? to do this is the same as to revive a dead man, and they may as well think of doing the one as the other; burnt stones being reckoned as dead, as Eben Ezra observes.

Now Tobiah the Ammonite was by him
Who was one of his brethren he spoke before, (Nehemiah 4:2) ,

and he said ;
in the like contemptuous and scoffing manner;

even that which they build, if a fox go up, he shall break down their
stone wall ;
signifying not only that it was so low that a fox could easily get up to it, or leap over it; but that the materials were so bad, and the work so poorly done, that the weight of a fox would break it down; of which creatures many were thereabout, since Jerusalem was desolate, see (5:18) .

Hear, O our God, for we are despised
Here begins the prayer of Nehemiah, who had been informed of what these men said in contempt of him, and his builders, and to whom he sent no answer, but applied to God:

and turn their reproach upon their own head ;
as they have despised and reproached us, let them be despised and reproached by their neighbours:

give them for a prey in the land of captivity ;
let them be carried captive, as we have been, and become a prey and booty to their enemies.

And cover not their iniquity, and let not their sin be blotted
out from before thee
Let it not go unpunished, and even let it not be pardoned; which is spoken, not from a private spirit of revenge, but from a public spirit for the glory of God, and his justice; and not as a mere imprecation, but as a prophecy of what would be the case, in like manner as many of David's petitions in the Psalms; and for this there was a good foundation, since God had threatened the Moabites and Ammonites with utter destruction:

for they have provoked thee to anger before the builders ;
by despising his people, and mocking at the work the Lord had called them to; and this they did publicly, and on purpose to discourage the workmen.