John Trapp on Nehemiah 6:5

Verſe 5. Then ſent Sanballat — the fifth time] So reſtleſſe are wicked perſons: their ſouls are violently toſſed about, as in a ſling, 1 Sam. 25.29. Etſi non aliquà docuiſſent, &c. Satan, their task-maſter, urgeth them; and when thou ſeeſt them moſt importunate, and outragious, Scito quia ab accenſore ſuo daemone perurgentur, ſaith Bernard, Know thou that the Devil pricks them, and kicks them on to it.

With an open Letter in his hand] Not ſealed as the manner is, for ſecrecy ſake. The Jews uſe to write upon the back of their Letters, Nun, Cheth, Shin: that is, Niddui Cherem and Shammatha, all ſorts of excommunication, to him that ſhall open them. But this Letter was purpoſely ſent open, that whoſo would might read it ere it came to Nehemiah's hand, and be warned of having hand in the pretended treaſon.