Albert Barnes Commentary Isaiah 22:20

"And it shall come to pass in that day, that I will call my servant Eliakim the son of Hilkiah:" — Isaiah 22:20 (ASV)

My servant Eliakim – A man who will be faithful to me; who will be trustworthy, and to whom the interests of the city may be safely confided; a man who will not seek to betray it into the hands of the enemy. Of Eliakim we know nothing more than what is stated here, and in (Isaiah 36:0). From that account it appears that he was prefect of the palace; that he was employed in a negotiation with the leader of the army of the Assyrians; and that he was in all things faithful to the trust reposed in him.

The son of Hilkiah – Kimchi supposes that this was the same as Azariah the son of Hilkiah, who might have had two names, and who was a ruler over the house of God in the time of Hezekiah (1 Chronicles 6:13).