The Egyptians were not satisfied with the mere possession of the texts of Thoth, when their souls were being weighed in the Great Scales in the Judgment Hall of Osiris, but they also wished Thoth to act as their Advocate on this dread occasion and to prove their innocence as he had proved that of Osiris before the great gods in prehistoric times. According to a very ancient Egyptian tradition, the god Osiris, who was originally the god of the principle of the fertility of the Nile, became incarnate on earth as the son of Geb, the Earth-god, and Nut, the Sky-goddess. He had two sisters, Isis and Nephthys, and one brother, Set; he married Isis and Set married Nephthys. Geb set Osiris on the throne of Egypt, and his rule was beneficent and the nation was happy and prosperous. Set marked this and became very jealous of his brother, and wished to slay him so that he might seize his throne and take possession of Isis, whose reputation as a devoted and loving wife and able manager filled the country. By some means or other Set did contrive to kill Osiris: according to one story he killed him by the side of a canal at Netat, near Abydos, and according to another he caused him to be drowned. Isis, accompanied by her sister Nephthys, went to Netat and rescued the body of her lord, and the two sisters, with the help of Anpu, a son of Ra the Sun-god, embalmed it. They then laid the body in a tomb, and a sycamore tree grew round it and flourished over the grave. A tradition which is found in the Pyramid Texts states that before Osiris was laid in his tomb, his wife Isis, by means of her magical powers, succeeded in restoring him to life temporarily, and made him beget of her an heir, who was called Horus. After the burial of Osiris, Isis retreated to the marshes in the Delta, and there she brought forth Horus. In order to avoid the persecution of Set, who on one occasion succeeded in killing Horus by the sting of a scorpion, she fled from place to place in the Delta, and lived a very unhappy life for some years. But Thoth helped her in all her difficulties and provided her with the words of power which restored Horus to life, and enabled her to pass unharmed among the crocodiles and other evil beasts that infested the waters of the Delta at that time.