Jeremiah 51:64

⁶⁴ And thou shalt say, Thus shall Babylon sink, and shall not rise from the evil that I will bring upon her: and they shall be weary. Thus far are the words of Jeremiah.

Four corners of the earth

In Revelation 7:1, this signifies all the whole spiritual world. It also signifies the whole of heaven in the effort to execute a last judgment on those stuck in the World of Spirits. (Apocalypse Revealed 342, Apocalypse Explained 417)