Albert Barnes Commentary 2 Kings 19:4

"It may be Jehovah thy God will hear all the words of Rabshakeh, whom the king of Assyria his master hath sent to defy the living God, and will rebuke the words which Jehovah thy God hath heard: wherefore lift up thy prayer for the remnant that is left." — 2 Kings 19:4 (ASV)

Will hear – That is, he will show that he has heard; he will notice and punish.

The living God – See the note on 1 Samuel 17:26.

And will reprove the words – Rather, he will reprove him for the words.

The remnant – That is, the kingdom of Judah, the only remnant of God’s people that was left after Galilee, Gilead, and Samaria had all been carried away captive.