John Calvin Commentary Isaiah 33:8

"The highways lie waste, the wayfaring man ceaseth: [the enemy] hath broken the covenant, he hath despised the cities, he regardeth not man." — Isaiah 33:8 (ASV)

The roads are deserted. He now adds that “the roads” will be shut up, so that no one will go in or out, which commonly happens when war has been declared. The Prophet appears to represent the ambassadors as declaring that from now on there will be no opportunity to carry on merchandise, and even that the highways will not be safe. It is immediately added:

They have violated the treaty. Some commentators view these words as a complaint made by hypocrites that God does not fulfill His promises. If these words were considered to refer to God, it would still not be necessary to say that such a complaint comes only from wicked men, because sometimes believers also quarrel with God in this way.

But I cannot approve of that interpretation. Therefore, I consider this to be part of the Prophet's description of the cruelty and insatiable rage of Sennacherib, in treacherously breaking the treaty he had previously made with Hezekiah.

For although he had promised that he would maintain peace, yet as soon as an opportunity presented itself for invading Judea, he violated his promise and made preparations for war. Such is also the meaning of the conclusion of the verse, that he hath despised the cities, he hath regarded no man, which means that his cruelty will be so great that he will not be restrained by shame or fear.