Surely you have heard what the kings of Assyria have done to all the other countries, devoting them to destruction. Will you then be spared?
Rabshakeh, having delivered his message and received no answer (whether he took this silence for a consent or a slight does not appear), left his army before Jerusalem, under the command of the other generals, and went himself to attend the king his master for further orders. He found him besieging Libnah, a city that had revolted from Judah, Kg2 8:22.
Commenting on 2 Kings 19:8-19
2Ki 19:10-11 ישּׁיאך אל: “let not thy God deceive thee,” i.e., do not allow yourself to be deceived by your confidence in your God. לאמר, to say, i.e., to think or believe, that Jerusalem will not be given, etc. To shatter this confidence, Sennacherib reminds him of the deeds of the Assyrian kings. להחרימם, to ban them, i.e., by smiting them with the ban.
Commenting on 2 Kings 19:10-11