Albert Barnes Commentary Nehemiah 9:6

"Thou art Jehovah, even thou alone; thou hast made heaven, the heaven of heavens, with all their host, the earth and all things that are thereon, the seas and all that is in them, and thou preservest them all; and the host of heaven worshippeth thee." — Nehemiah 9:6 (ASV)

The host of heaven worships you—that is, the angels. See 1 Kings 22:19; Psalms 103:21.