The Circumcision of Gershom
Moses was imprisoned in a deep dungeon in Jethro's house, and received as food only small portions of bread and water. He would have died of hunger had not Zipporah, to whom Moses had before his captivity made an offer of marriage by the well, devised a plan by which she no longer went out to pasture the sheep, but remained at home to attend to the household, being thereby enabled to supply Moses with food without her father's knowledge. After ten (or seven) years Zipporah reminded her father that he had at one time cast a man into the dungeon, who must have died long ago; but if he were still living he must be a just man whom God had kept alive by a miracle. Jethro went to the dungeon and called Moses, who answered immediately. As Jethro found Moses praying, he really believed that he had been saved by a miracle, and liberated him.
Jethro had planted in his garden a marvelous rod, which had been created on the sixth day of the Creation, on Friday afternoon, and had been given to Adam. This curious rod had been handed down through Enoch, Shem, Abraham, Isaac, and Jacob to Joseph, at whose death it came into the possession of Pharaoh's court. Jethro, who saw it there, stole it and planted it in his garden. On the rod were engraved the name of God and the initials of the ten plagues destined for Egypt. Jethro asked every one who wished to marry one of his daughters to pull up the rod; but no suitor had yet succeeded in doing so. Moses, on being set at liberty, walked in the garden, saw the rod, and read the inscription. He easily pulled it out of the ground and used it for a staff Jethro thereby recognized Moses as the deliverer of Israel, and gave him the virtuous Zipporah as wife, together with much money ("Book of Jasher" "D. Y.," and "Midrash Wayosha" l.c.).
Jethro stipulated that the first-born son of the marriage should adopt Jethro's pagan belief, while all the other children might be reared as Jews; and Moses agreed thereto (Mek., Yitro, 1 ). According to "Midrash Wayosha" l.c., one-half of the children of this marriage were to belong to Judaism and one-half to paganism. When therefore his son Gershom — who subsequently became the father of Jonathan — was born, Moses, under his agreement with Jethro, could not circumcise him ("Book of Jasher" l.c.). Moses, therefore, went with his wife and child (another version says that both of his sons were then already born) to Egypt.
On the way he met Satan, or Mastema, as he is called in the Book of Jubilees (xlviii. 2), in the guise of a serpent, which proceeded to swallow Moses, and had ingested the upper part of his body, when he stopped. Zipporah seeing this, concluded that the serpent's action was because her son had not been circumcised (Ned. 31b-32a; Exodus Rabba v.), whereupon she circumcised him and smeared some of the blood on Moses' feet. A heavenly voice (bat kol) was then heard commanding the serpent to disgorge the half-swallowed Moses, which it immediately did. When Moses came into Egypt he met his old enemies Dathan and Abiram, and when they asked him what he was seeking in Egypt, he immediately returned to Midian ("Midrash Wayosha" l.c.).
Read more about this topic: Moses In Rabbinic Literature