The oldest Mss of Jude 5 say ‘Jesus brought (or having saved) His people out of Egypt’. Christ was to go before them through the wilderness but it turned out He followed them. Christ was the Mediator as the Law was given at Mt. Sinai. He is also the Mediator of the New Covenant as well.. He descended on to Mt. Sinai in the Psalms for the giving of the Law and as in Ephesians He ascended for the purposes of the gospel.