Rab-shakeh returned to the king, to give him an account of the treaty, and to advise with him what was further to be done; leaving behind him the army under the other commanders, mentioned 2 Kings 18:17, as is most probable from the other threatening message here following; which would have been very unsuitable, if his siege had been raised. He was departed from Lachish; not being able to take it.
Related Commentaries of 2 Kings 19:8
2 Kings 19:8
8 So Rabshakeh returned, and found the king of Assyria warring against Libnah: for he had heard that he was departed from Lachish.