Adam Clarke on Exodus 8:22

I will sever in that day - הפליתי hiphleythi, has been translated by some good critics, I will miraculously separate; so the Vulgate: Faciam mirabilem, "I will do a marvellous thing." And the Septuagint, παραδοξασω, I will render illustrious the land of Goshen in that day; and this he did, by exempting that land, and its inhabitants the Israelites, from the plagues by which he afflicted the land of Egypt.