Originated from the mother of gods in Egyptian mythology. In the beginning, this world was created by the god of sun named Atum, and the world was built with the sky, ether, air, earth, water, underworld, etc. The god who governed sky was Nut. Later, she married the god of earth, Geb, and gave birth to many gods including Osiris, Seth, Isis, and so on. Hmm, I really envy the god Geb.