When people pray in the Bible, it means they are opening up their internal states. When it is the Lord praying, or a figure who represents the Lord, that opening up reveals the Lord's inmost love and intention, and means that hidden things will be revealed. When others pray the meaning is less exalted, representing worshiping God from a love of other people.

(References: Apocalypse Revealed 278; Arcana Coelestia 2535, 2580; The Apocalypse Explained 325 [1-3])