Studio
9 joining one unto another [are] their wings, they turn not round in their going, each straight forward they go.
In Genesis 18:7; 2 Samuel 12:4, this symbolizes earthly goodness. (Arcana Coelestia 2181)
18 For, behold, I have made you this day a fortified city, and an iron pillar, and bronze walls, against the whole land, against the kings of Judah, against its princes, against its priests, and against the people of the land.