v1-2: A personal attack on Nehemiah. Sanballat and Tobiah offered to meet with him, but Nehemiah discerned their real intention, "they were scheming to do me harm."
The enemies of the Jewish people rightly identified Nehemiah as the key leader; had they been successful in killing him, then the progress of the work would have doubtless suffered.
v3: Nehemiah's reply; he remained committed to the work; he was single-minded. He recognised the importance of the work, and his own role in it. No false humility here.
To leave the work and to meet with the enemies would have been a step "down", as in Luke 10.30; we are not unaware of the enemy's schemes (2 Cor 2.11).
v4: Repeated attacks must be repeatedly resisted; just as Joseph resisted "day by day" (Gen 39.10).
v5-7: Sanballat sent an open letter, designed to generate prejudice against the Jews in general, and against Nehemiah in particular.
"It is reported among the nations - and Gashmu (not Geshem) knows", i.e; 'everybody knows!' This was an attempt to give credibility to lies.
The letter was designed to make Nehemiah appear self-seeking, and that he would rebel against the emperor. A similar accusation occurred in Ezra 4.13-16, which proved successful in delaying building work. We would call this slander.
v8-9: Nehemiah's response, in prayer and action.
His letter of reply was brief, and carefully measured; we are not to spend lots of time casting pearls before swine; a long reply here would have been unnecessary; contrast Jephthah's words in Judg 11. Nehemiah recognised Sanballat's deceit, "You are just making it up out of your head." He saw the real motive, was to see the building of the wall stopped.
Nehemiah's prayer indicated a continuing trust in God.
v10: The personal attack from outside was followed by another attack from within. Shemaiah invited Nehemiah to hide in the temple to save his life. Beware inner rooms of secret, Matt 24.26.
The exact timing of this temptation is not clear, but it must have happened before the wall was completed. The writer is not concerned with a detailed chronology, but with exposing the various attacks upon Nehemiah, and showing how he remained victorious and faithful.
v11: Nehemiah was not afraid of any threats.
v12: Nehemiah perceived the reality, that Shemaiah was in the pay of Sanballat and Tobiah. As in v2, here is spiritual discernment in Nehemiah, seeing deceitful motives behind fine-sounding words.
v13: Shemaiah had 'prophesied' against Nehemiah to lead him into sin, and thus spoil his testimony and godly reputation.
v14: These words, in prayer to God, imply that there were a number of false prophets. Nehemiah doubtless faced numerous trials, and only some are recorded for us. How important it is to have discernment.
v15: The actual building of the wall took only 52 days, less time than Nehemiah's personal preparation; it seems God is more interested in us, than in what we do.
v16: See Matt 5.16; their light shone before men.
v17-19: Further attacks on Nehemiah. Many in Judah were loyal to Tobiah, and some were allied through marriage, as in 13.28. These people could only report Nehemiah's good deeds. Like Daniel, he maintained a testimony of integrity.