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)

Fowl signify spiritual truth; a bird, natural truth; and a winged thing, sensual truth. Fowl of heaven, as in Hosea 2:18, signify the affections of truth; and reptiles of the earth, the affection of the knowledges of truth and good. Fowl signify thoughts, and all that creeps on the ground, the sensual principle. Fowl signify intellectual things.

(References: Arcana Coelestia 777; Hosea 2)