For I do not want you to be ignorant of the fact, brothers, that our forefathers were all under the cloud and that they all passed through the sea [1 Cor 10:1]
Ask any Christian and this makes perfect sense because they were born with this inherited notion but ask any Jew or Samaritan about this proposition and they will laugh. 'But the waters never touched our forefathers,' they will say. 'The Torah is explicit about this. They walked on dry land while the water was lined up like two columns on each side.'
The only people that were in the water were the Egyptians and as I have noted many times, the Marcionite name of our First Letter to the Corinthians was 'to the Alexandrians.'
I think I would call this a breakthrough, wouldn't you ...
UPDATE: So I was driving to work thinking (I actually bumped into the person in front of me in the line at the drive thru Starbucks) this explanation of a Markan ritual interest in the drowned Egyptians explains the parallel fascination with the number eight (the Ogdoad). I have written about this before but I can take the Jewish and Samaritan understanding of the TIMING of the Crossing of the Sea to the next level.
The Israelites are ALWAYS understood to have crossed the sea as the seventh day 'went out' into the eighth. This is clearly taken to be symbolic of the future advent of the messiah, the kingdom of heaven etc.because we are in transition from the Hebdomad to the Ogdoad.
But think about the poor Egyptians for a moment. If the Israelites make it through the sea as the seventh day was transitioning to the eighth and then the waters come crashing down on the Egyptians once the Israelites have reached dry land, take a guess in what day this event must have occurred? Yes, the eighth day of the feast of Unleavened Bread.
Interestingly Jews also add a day to the feast for those living outside of Israel too. But I digress.
I am absolutely certain that Secret Mark's first addition featuring an initiated dead youth, the Marcosian ἀπολύτρωσις ritual and the Marcionite baptism on behalf all go back to this central idea. Now back to the drudgery of making a living ...
UPDATE 2: I found a great number of Patristic references to baptism as developing from the drowning of the Egyptians in the Sea:
But, if there are any who say that sins are only superficially put away in baptism, what can be more against the faith than such preaching, whereby they would fain undo the very sacrament of faith, wherein principally the soul is bound to the mystery of heavenly cleanness, cleanness, that, being completely absolved from all sins, it may cleave to Him alone of Whom the Prophet says, But it is good for me to cleave to God (Ps. lxxii. 28157)? For certainly the passage of the Red Sea was a figure of holy baptism, in which the enemies behind died, but others were found in front in the wilderness. And so to all who are bathed in holy baptism all their past sins are remitted, since their sins die behind them even as did the Egyptian enemies. But in the wilderness we find other enemies, since, while we live in this life, before reaching the country of promise, many temptations harass us, and hasten to bar our way as we are wending to the land of the living. Whosoever says, then, that sins are not entirely put away in baptism, let him say that the Egyptians did not really die in the Red Sea. But, if he acknowledges that the Egyptians really died, he must needs acknowledge that sins die entirely in baptism, since surely the truth avails more in our absolution than the shadow of the truth.[Gregory the Great, Epistle LXV]
dating back to conversations with his grandfather, Gaston Frank. "He said we represent one of the last descendants of the Frankist Jewish faith in the world," he muses. "I grew up thinking that our family was something like the Last of the Mohicans."