Allusions in Jewish rabbinic literature to the Biblical character Jethro, the father-in-law of Moses, contain various expansions, elaborations and inferences beyond what is presented in the text of the Bible itself.
[2] It became, however, generally accepted that he had seven names: "Reuel", "Jether", "Jethro", "Hobab", "Heber", "Keni",[3] and "Putiel"; Eleazar's father-in-law (Exodus 6:25) being identified with Jethro by interpreting his name either as "he who abandoned idolatry" or as "who fattened calves for the sake of sacrifices to the idol".
[7] Some commentators maintain that when Pharaoh asked his advisors about how to go about outsmarting/exterminating Israel, Jethro promptly fled the scene while Job remained silent and Balaam suggested to enslave them.
Moses did not go out alone to meet his father-in-law; but was accompanied by Aaron, Nadab, Abihu, and the seventy elders of Israel to honor Jethro.
[13] The words vayihad Yitro (Exodus 18:9), generally translated "and Jethro rejoiced," are interpreted by the Talmudists as "he circumcised himself"; or "he felt a stinging in his flesh"; that is to say, he was sorry for the loss of the Egyptians, his former coreligionists.