'Lord of Hosts' in the Bible

Elisha said, “As the Lord of hosts (armies) lives, before whom I stand, were it not that I have regard for Jehoshaphat king of Judah, I would not look at you nor see you [king of Israel].

For a remnant will go forth from Jerusalem, and [a band of] survivors from Mount Zion. The zeal of the Lord of hosts shall perform this.