isaiah 8:21 And they shall pass through it, hardly bestead and hungry: and it shall come to pass, that when they shall be hungry, they shall fret themselves, and curse their king and their God, and look upward. - Free Bible Online

      21, 22. More detailed description of the despair, which they shall fall into, who sought necromancy instead of God; Isa 8:20 implies that too late they shall see how much better it would have been for them to have sought "to the law," &c. (De 32:31). But now they are given over to despair. Therefore, while seeing the truth of God, they only "curse their King and God"; foreshadowing the future, like conduct of those belonging to the "kingdom of the beast," when they shall be visited with divine plagues (Re 16:11; compare Jer 18:12).
      through it--namely, the land.
      hardly bestead--oppressed with anxiety.
      hungry--a more grievous famine than the temporary one in Ahaz' time, owing to Assyria; then there was some food, but none now (Isa 7:15, 22; Le 26:3-5, 14-16, 20).
      their king . . . God--Jehovah, King of the Jews (Ps 5:2; 68:24).
      look upward . . . unto the earth--Whether they look up to heaven, or down towards the land of Judea, nothing but despair shall present itself.
      dimness of anguish--darkness of distress (Pr 1:27).
      driven to darkness--rather, "thick darkness" (Jer 23:12). Driven onward, as by a sweeping storm. The Jewish rejection of "their King and God," Messiah, was followed by all these awful calamities.

JFB.