In the Bible, things that are lower down, or under, physically, generally represent things that are lower or more external spiritually. In some cases, the lower things have been separated and put away to protect the good, but in others, it can mean that a less exalted idea or good desire is supporting a more exalted one.

(References: Arcana Coelestia 4564 [1-2], 8610, 9656)

A 'void', or 'Vacuity' denotes a person's state before regeneration. From Arcana Coelestia 7: "The first state is the state which precedes, both the state existing from earliest childhood onwards and that existing immediately before regeneration; and it is called a void, emptiness, and thick darkness.

In Genesis 1:2, this signifies lacking good, as with man's state before regeneration. (Arcana Coelestia 17)

In Psalm 89:39, this signifies that the Jewish nation had destroyed its conjunction with the Lord and the church. (The Inner Meaning of the Prophets and Psalms 339)