If you look around the universe you will see various examples of rotating bodies. They are all aggregations of matter. They are in pretty well defined structures. Consider the rings of Saturn. As they aggregate and take on more mass they will become spherical and the unequal distribution causes wobbling that eventually stabaiizes as rotation.
The moon was once a ring of particulates flung out by the collision. Time and gravity collected the particles.
And will again be. Currently the moon is receding from the earth and will continue to do so until the lunar month and earth day are both about 47 current earth days long. Then the Moon will gradually spiral in on the earth, its orbit becoming ever smaller, until falls within the Roche limit at which point the earth's gravity will disrupt it and it will quickly become a ring, or a series of rings around the earth.