This verse is part of a propaganda speech delivered by Rabshakeh, a high-ranking official in the Assyrian army, on behalf of King Sennacherib. The Assyrians had besieged Jerusalem, and Rabshakeh was trying to demoralize the people of Judah and convince them to surrender.

Here's a breakdown of what the verse means:

"Thus says the king": This establishes that Rabshakeh is speaking with the authority of the powerful Assyrian King Sennacherib. It is meant to emphasize the threat.

"Don't let Hezekiah deceive you": Hezekiah was the King of Judah at the time. Rabshakeh is accusing Hezekiah of misleading his people. He's trying to sow doubt and distrust.

"for he will not be able to deliver you out of his hand": This is the core of the message. Rabshakeh is declaring that Hezekiah is powerless to save the people of Jerusalem from the Assyrian army. The "his hand" refers to Sennacherib's, meaning the Assyrian king's, power and control. The Assyrians believed their military might was invincible.

In essence, the verse is a threat and a piece of psychological warfare. Rabshakeh is telling the people of Jerusalem not to believe in their king's promises of deliverance, because the Assyrian king is too strong to be defeated. It is intended to break their spirit and make them give up without a fight.

The verse is significant within the broader narrative because it highlights the immense power of the Assyrian empire at the time and the desperate situation faced by Judah. It also sets the stage for Hezekiah's response, which involves prayer and reliance on God.