The firmament of heaven represents mutual love. The firmament, as in Genesis 1, signifies the internal man.

(References: Arcana Coelestia 24)

In Genesis 8:8, this signifies what people in the church have in them, the word ground being used because this is a person's first stage in becoming a church.Later, the face of the ground being dried up in Genesis 8:13 signifies regeneration when falsities no longer appeared.

(References: Arcana Coelestia 898, Genesis 13)