Let not their sin be blotted out from before thee; let their wickedness be in thy sight, so as to bring down deserved judgments it. upon them, that either they may be convinced and reformed, or others may be warned by their example. God is said to cover or hide sin when he forbears to punish. They have provoked thee to anger before the builders, i.e. they have not only provoked us builders, but thee also. Or, they have provoked or derided the builders to their face, i.e. openly and impudently, in contempt of God, and of this work, which is done by his direction and encouragement.
Related Commentaries of Nehemiah 4:5
Nehemiah 4:5
5 And cover not their iniquity, and let not their sin be blotted out from before thee: for they have provoked thee to anger before the builders.