In Egyptian mythology, Sia was the personification of intellect. He, and Hu, were created from a drop of blood that came from Ra's penis. Sia represented knowledge, while Hu was the divine utterance and command. They were part of the crew of Ra's sun boat; Sia stood at the prow (except at night, when Upuaut rested there) with Hu right behind him. Sia was shown holding a papyrus.
