I do think that the Josianic return to the archaic form of the Passover is appropriate and, indeed, historical. Josiah does go back to a different, earlier tradition, the time of a central sanctuary in which the law code was read. But then there were accretions to the Book of Deuteronomy.
Frank Moore CrossFurthermore, I think there was, in fact, a celebration of Passover in the era of the Judges in which the epic was recited in the context of the central sanctuary. That tradition was displaced by the Feast of Enthronement beginning in the Solomonic era.
Frank Moore CrossWe are thrown back on the text, for the most part. Archaeology can give us background. It doesn't either confirm or disprove the Bible, but it may illuminate it.
Frank Moore Cross[Sacrifice of Isaac] is a major theme of the so-called Elohist [one authorial strand in the Pentateuch]. It is marked by all of his linguistic characteristics, and so on. We cannot determine what is historical and what isn't. As literary critics, we would understand the importance of this for understanding life, destiny. But the historical question must be left with a question mark.
Frank Moore Cross