https://en.wikipedia.org/wiki/Moses_and_Monotheism#Summary
In Freud's retelling of the events, Moses led only his close followers into freedom (during an unstable period in Ancient Egyptian history after Akhenaten's death ca. 1350 BCE), that they subsequently killed the Egyptian Moses in rebellion, and still later joined with another monotheistic tribe in Midian who worshipped a volcano god called Yahweh.[4][11] Freud supposed that the monotheistic solar god Aten of the Egyptian Moses was fused with Yahweh, the Midianite volcano god, and that the deeds of Moses were ascribed to a Midianite priest who also came to be called Moses.[12] Moses, in other words, is a composite figure, from whose biography the uprising and murder of the original Egyptian Amarna-cult priest has been excised.[4]
Freud explains that centuries after the murder of the Egyptian Moses, the rebels regretted their action, thus forming the concept of the Messiah as a hope for the return of Moses as the Saviour of the Israelites. Freud claimed that repressed (or censored) collective guilt stemming from the murder of Moses was passed down through the generations; leading the Jews to neurotic expressions of legalistically religious sentiment to disperse or cope with their inheritance of trauma and guilt. In many respects, the book reiterates the theogony that Freud first argued in Totem and Taboo,[13] as Freud acknowledges in the text of Moses & Monotheism on several occasions. For example, he writes:
