The birth narrative of Moses has a striking similarity to the story of the birth of Sargon of Akkad (c. 2334-2279 BC)…The date of composition of the Sargon birth narrative is unknown, but it is universally regarded as pseudepigraphal; that is, Sargon I did not write it. Theoretically, it could have been written at any time from soon after the death of Sargon until the reign of Ashurbanipal (r. c. 668-627 BC).
First, [Brian] Lewis only succeeds in creating the appearance of a strong parallel between the Moses and Sargon stories by "stripping away" (his term) elements in the story not paralleled in Sargon. These include that (1) genocide is the motivation for hiding Moses, (2) Moses is hidden for three months, (3) Moses' sister watches over him, (4) a person of high rank, Pharaoh's daughter, adopts Moses, and (5), Moses' own mother nurses him.
But one cannot simply excise everything in story B that is unlike story A, and then declare store is A and B to be parallel. Unless one has prior knowledge that there is a Vorlage [i.e. copy of a source document] to a story B that is dependent on story A,one has no basis for recreating this putative Vorlage. Otherwise, any time two stories had something in common,one could declare the Vorlage of B to be dependent on A simply by excising as a later accretion everything in B that is different from A.
Second, the parallels that Lewis claims for Moses and Sargon are for the most part illusory, and there are numerous differences. For example, it is not correct to say that in both cases the hero is born to a mother of high rank. This is true of Sargon, born to a "high priestess," but Moses' mother is simply a "Levite woman" (Exod 2:1). In addition, Moses is not truly abandoned or even set adrift on the river, as Sargon is. Moses' mother places his basket among the reeds so that he will not drift away (and also Moses' sister watches over him.
Sargon is raised by a peasant and is set to work in an orchard; Moses is raised in the aristocracy. The Moses story has an account of the hero's naming, and the name reflects the fact that the child was set on a river (Exod 2:10); the Sargon story does not.
Even the most obvious parallel, setting the baby in a basket, is probably not significant. One can hardly doubt that in the ancient world there were many examples of women who for some reason (poverty, disgrace, danger, etc.) decided that they could not keep their children. These women would, as in the more recent counterpart of putting a baby in a basket on a doorstep, place their children outside either to die of exposure or to cast upon the charity of others. In a country such as Greece, with many mountains but with no significant rivers, the logical place to do this was on a mountain side (as in the story of Oedipus, whom a shepherd was supposed to abandon on a mountain). In the cases of Mesopotamia and Egypt, two regions dominated by rivers, the logical place to do this was on the Euphrates or the Nile. In short, the setting of the baby in a basket onto a river is simply something that arises from the environment; it is not a motif useful for establishing literary dependence. D. Garrett, A Commentary on Exodus (Kregel 2014), 172-74.