The dove is the Spirit seeking a place to settle, and it finds none while the waters still cover everything. The flood is the old confusion not yet drained, the state a person has not yet let subside. So the dove returns to the ark. The ark is man himself, the vessel that holds God. Nothing descends and rests until the surface within is calm enough to receive it.
The hand reaching out to draw the dove in is a person taking the assurance back into himself. Every event in a life was planted earlier by an imaginal act, seedtime and harvest running as one unbroken law, so only lovely seeds are worth planting. As the inner waters recede, a new world rises out of the old. The Spirit finally rests when the state a person holds has grown quiet and sure. What settles within is what appears without.