Origen of Alexandria, Against Celsus 6

Celsus, then, never became a fair examiner of what Egyptians say on one hand and Hebrews on the other; instead, he was prepossessed, as if by partisans of the Egyptians. To those who wronged the foreigners he assented as if they spoke truth, while he claimed that the wronged Hebrews, who were rebelling, left Egypt — failing to see how a rebellious multitude of Egyptians that large could not have come into existence, taking the rebellion as its beginning, becoming a nation at the same time as it rebelled, and changing its dialect so that those who until then had been using the Egyptian tongue might suddenly adopt the Hebrew one. Let us grant, for the sake of hypothesis, that they left Egypt hating both it and its native speech; how then did they not rather use the Syrian dialect afterward, or the Phoenician, but instead established the Hebrew dialect, distinct from both? This is what my argument aims to show: that it is false that some Egyptians, being of that stock, rebelled against Egyptians, left Egypt, came to Palestine, and settled in what is now called Judea. For the Hebrews possessed a paternal dialect before their descent into Egypt, and there were Hebrew letters, different from Egyptian ones, which Moses used to write the five holy books believed by the Jews.