A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
neh 6:2SANBALLAT PRACTISES AGAINST NEHEMIAH BY INSIDIOUS ATTEMPTS. (Neh. 6:1-19)
Then Sanballat and Geshem sent unto me--The Samaritan leaders, convinced that they could not overcome Nehemiah by open arms, resolved to gain advantage over him by deceit and stratagem. With this in view, under pretext of terminating their differences in an amicable manner, they invited him to a conference. The place of rendezvous was fixed "in some one of the villages in the plain of Ono." "In the villages" is, Hebrew, "in Cephirim," or "Chephirah," the name of a town in the territory of Benjamin (Jos 9:17; Jos 18:26). Nehemiah, however, apprehensive of some intended mischief, prudently declined the invitation. Though it was repeated four times, [Nehemiah's] uniform answer was that his presence could not be dispensed with from the important work in which he was engaged. This was one, though not the only, reason. The principal ground of his refusal was that his seizure or death at their hands would certainly put a stop to the further progress of the fortifications.
neh 6:5Then sent Sanballat his servant . . . the fifth time with an open letter in his hand--In Western Asia, letters, after being rolled up like a map, are flattened to the breadth of an inch; and instead of being sealed, they are pasted at the ends. In Eastern Asia, the Persians make up their letters in the form of a roll about six inches long, and a bit of paper is fastened round it with gum, and sealed with an impression of ink, which resembles our printers' ink, but it is not so thick. Letters were, and are still, sent to persons of distinction in a bag or purse, and even to equals they are enclosed--the tie being made with a colored ribbon. But to inferiors, or persons who are to be treated contemptuously, the letters were sent open--that is, not enclosed in a bag. Nehemiah, accustomed to the punctillious ceremonial of the Persian court, would at once notice the want of the usual formality and know that it was from designed disrespect. The strain of the letter was equally insolent. It was to this effect: The fortifications with which he was so busy were intended to strengthen his position in the view of a meditated revolt: he had engaged prophets to incite the people to enter into his design and support his claim to be their native king; and, to stop the circulation of such reports, which would soon reach the court, he was earnestly besought to come to the wished-for conference. Nehemiah, strong in the consciousness of his own integrity, and penetrating the purpose of this shallow artifice, replied that there were no rumors of the kind described, that the idea of a revolt and the stimulating addresses of hired demagogues were stories of the writer's own invention, and that he declined now, as formerly, to leave his work.
neh 6:10Afterward I came unto the house of Shemaiah, &c.--This man was the son of a priest, who was an intimate and confidential friend of Nehemiah. The young man claimed to be endowed with the gift of prophecy. Having been secretly bribed by Sanballat, he, in his pretended capacity of prophet, told Nehemiah that his enemies were that night to make an attempt upon his life. He advised him, at the same time, to consult his safety by concealing himself in the sanctuary, a crypt which, from its sanctity, was strong and secure. But the noble-minded governor determined at all hazards to remain at his post, and not bring discredit on the cause of God and religion by his unworthy cowardice in leaving the temple and city unprotected. This plot, together with a secret collusion between the enemy and the nobles of Judah who were favorably disposed towards the bad Samaritan in consequence of his Jewish connections (Neh 6:18), the undaunted courage and vigilance of Nehemiah were enabled, with the blessing of God, to defeat, and the erection of the walls thus built in troublous times (Dan 9:25) was happily completed (Neh 6:15) in the brief space of fifty-two days. So rapid execution, even supposing some parts of the old wall standing, cannot be sufficiently accounted for, except by the consideration that the builders labored with the ardor of religious zeal, as men employed in the work of God.