Notes on the Bible, by Albert Barnes, [1834], at sacred-texts.com
Upon the gates - Rather, "in the gates." This work would naturally be delayed until the last phase.
The choice made of Ono, on the skirts of Benjamin, 25 or 30 miles from Jerusalem, as the meeting-place, was, no doubt, in order to draw Nehemiah to a distance from his supporters, that so an attack might be made on him with a better chance of success.
The letter was "open," in order that the contents might be generally known, and that the Jews, alarmed at the threats contained in it, might refuse to continue the work.
Who was shut up - On account, probably, of some legal uncleaness. Compare Jer 36:5.
Would go into the temple to save his life - Rather "could go into the temple and live." For a layman to enter the sanctuary was a capital offence (see Num 18:7).
The existence of a party among the Jews who sided with Sanballat and lent themselves to his schemes, is here for the first time indicated. Compare Neh 6:14, Neh 6:17-19; Neh 13:4-5, Neh 13:28.
Noadiah is not elsewhere mentioned. The examples of Miriam, Deborah, Huldah, and Anna, show that the prophetical gift was occasionally bestowed upon women (Kg2 22:14 note).
Elul - The sixth month, corresponding to the latter part of August and the beginning of September.
In fifty and two days - Josephus states that the repairs of the wall occupied two years and four months. But Nehemiah's narrative is thoroughly consistent with itself, and contains in it nothing that is improbable. The walls everywhere existed at the time that he commenced his task, and only needed repairs. The work was partitioned among at least 37 working parties, who labored simultaneously, with material ready at hand; and, notwithstanding all menaces, uninterruptedly.
Though Tobiah is called "the servant" or "slave" Neh 2:10, Neh 2:19, and was perhaps a bought slave of Sanballat's, yet he was in such a position that Jewish nobles readily contracted affinity with him. This is quite in harmony with the practice of the East, where slaves often fill high positions and make great marriages.