Now, to be clear. I'm not saying that everything said below is true and correct. I'm just recaping what Ms. Armstrong says. Feel free to point out any problems or alternative points of view that you like.
Ms. Armstrong begins in 597 BCE, when Judah rebelled against the Babylonian empire, and was crushed for the trouble. This was the beginning of the Jewish exile in Babylon. While not all Jews were removed, many were, including their king, priests and military leaders. (Solomon's temple was burned to the ground following a second rebellion in 586 BCE.) The belief of the Jews who were taken into exile was that this was a divine punishment for a failure on their part to keep the covenant with God, and so they turned part of the energies to discovering a way to correct this imbalance.
Into this environment came the prophet Ezekiel. (Though Armstrong would never refer to him *as* the prophet Ezekiel. He sparked a prophetic movement among the exiles. An attempt to find reason behind their humiliation and defeat and loss of the homeland that God had promised them.
The displaced Jews had brought a number of scrolls with them, though, according to the author they did not regard them as sacrosanct, and felt free to add to them as they saw fit. Though she offers no explanation as to how she comes to this conclusion. This statement lacks even a simple citation to another work. It's simply something that she states, over and over again. Perhaps in the hope that repetition will make it so? She claims that the story of heavenly tablets gifted to mankind imparting secret, divine knowledge were common in the Middle East, and so the story of Moses and the giving of the Law on Mount Sinai were nothing special.
Then, she goes back to the beginning, as it were. The Jewish people, in 1200 BCE, or thereabouts, were living tribal lives in the Canaanite highlands, and their history, along with religious tales, were all oral. The Jews lived in twelve tribes, bound together by a common ancestry and shared history - they believed that they were the 'family of Yahweh'. They had common stories, but each tribe, each area, had a different focus, a different emphasis to their stories.
'The priests of Dan, in the extreme north, for example, believed that they were descended from Moses; Abraham, the father of the whole nation, had lived in Hebron and was especially popular in the south. At Gilgal, the local tribes celebrated Israel's miraculous entry into the Promised Land, when the waters of the river Jordan had miraculously parted to let them through. The people of Shechem annually renewed the covenant that Joshua had made with Yahweh after his conquest of Canaan.'
The Books of Moses where not, in fact, written by Moses. They had three 'authors', or rather, three texts that were similar, and eventually merged together to form one narrative. They are broken up into 'E' for the Elohim text, 'J' for the Yahweh text, and a later addition 'P' or the priestly texts. Keep in mind, of course, that the E & J 'texts' were oral traditions, not actual written text. They wouldn't be set down until later.
In 622 BCE, during the renovation of the temple, a priest found the lost 'scroll of the Law', and it was 'reintroduced' to the Jewish people. Ms. Armstrong appears to believe that this was, in fact, a largely invented event, with the 'found' scroll being, in fact, a new one that the priests had written themselves. In any case, the 'Deuteronomists' attributed the scroll to Moses, and taught the people that this was the Law from the beginning, and that it was their falling away from it that had led to the enslavement of the Jewish people for so long.
It was this new/old Law that the exiles took with them into Babylon. In Babylon, supposedly, the 'P' layer was added - the books of Numbers and Leviticus were added to the extant texts. The 'P' authors are the ones who suggested that the entire Jewish population observe the purity laws as though they were serving in the temple, as a way to keep themselves separate and holy even while surrounded by the Babylonian idolators.
In 539 Cyrus, king of Persia, allowed the Jews to return to their homeland. Many chose to remain, but those that returned took back with them the books of Genesis, Exodus, Leviticus, Numbers, Deuteronomy, Joshua, Judges, Samuel and Kings. Along with anthologies of the oracles of the prophets and a hymn book. This was the beginning, the seed of the Hebrew Bible. They also took with them a conviction that their Yahwism was the only authentic Jewish faith.