On your HJ-3a page you write:
1Co5:6-8 "Your boasting is not good. Don't you know that a little yeast works through the whole batch of dough? Get rid of the old yeast that you may be a new batch without yeast--as you really are [if there was no boasting!]. For Christ, our Passover, has been sacrificed. Therefore let us keep the Festival, not with the old yeast, the yeast of malice and wickedness, but with bread without yeast, the bread of sincerity and truth."
Paul's imagery relates to the Passover (one particular day) and the overlapping Festival of the unleavened bread (14 days), when bread without yeast (a symbol of purity "sincerity and truth") is eaten, instead of the leavened bread (symbol of impurity "malice and wickedness"). Naturally, Christ's sacrifice is associated with Passover (the day in the year) as a turning point: before, "malice and wickedness"; then and after "sincerity and truth".
Now, I agree that Paul so clearly calling Christ "our Passover" and relating his death to the Feast of Unleavened Bread might certainly be enough to inspire later Christians to assign Jesus' death to the time of Passover. However, there may be more to the Passover connection than this. The very words of institution in 1 Corinthians 11.24: τοῦτο ποιεῖτε εἰς τὴν ἐμὴν ἀνάμνησιν ("do this in my memory"), seem to many to be inspired by the focus on memory during Passover season, as directed in Exodus 12.14: καὶ ἔσται ἡ ἡμέρα ὑμῖν αὕτη μνημόσυνον ("and this day shall be a memorial for you").
And this match-up may tip the scales for me; it rather looks as though Paul himself (assuming for the sake of argument that the passage is not an interpolation) is thinking of the eucharistic meal as some kind of Passover meal. That is, the connection between Jesus' death and the Passover may be more than metaphorical for Paul; he may think of Jesus himself having inaugurated the eucharist specifically with the Passover in mind.
Do you see a connection between τοῦτο ποιεῖτε εἰς τὴν ἐμὴν ἀνάμνησιν and καὶ ἔσται ἡ ἡμέρα ὑμῖν αὕτη μνημόσυνον? Or do you think that is parallelomania running rampant again?
Ben.