Then sent Sanballat his servant unto me in like manner the fifth time with an open letter in his hand; With an open letter in his hand - This was an insult to a person of Nehemiah's quality: as letters sent to chiefs and governors in the East are always carefully folded up, and put in costly silken bags, and these carefully sealed. The circumstance is thus marked to show the contempt he (Sanballat) had for him.
Related Commentaries of Nehemiah 6:5
Nehemiah 6:5
5 Then sent Sanballat his servant unto me in like manner the fifth time with an open letter in his hand;