Albert Barnes Commentary Isaiah 39:5

"Then said Isaiah to Hezekiah, Hear the word of Jehovah of hosts:" — Isaiah 39:5 (ASV)

Hear the word of the Lord of hosts — Hear what the mighty God who rules in heaven says of this. This is an instance of great fidelity on the part of the prophet. He felt himself sent from God in a solemn manner to rebuke sin in a monarch, and a pious monarch. It is an instance that strikingly resembles the boldness and faithfulness of Nathan when he went to David and said, Thou art the man (2 Samuel 12:7).