Nehemiah 6:5

Then sent Sanballat his servant unto me in like manner the fifth time with an open letter in his hand, the intention being to stir up the Jews against Nehemiah, (at the same time, a letter which was not sealed and not enclosed in a special covering, as the custom of the time prescribed, was not so much informal as designedly disrespectful, a fact which Nehemiah was bound to notice at once,)