Charles Ellicott Commentary Exodus 10:13

"And Moses stretched forth his rod over the land of Egypt, and Jehovah brought an east wind upon the land all that day, and all the night; and when it was morning, the east wind brought the locusts." — Exodus 10:13 (ASV)

An east wind. —The Septuagint translates as νότον, “a south wind,” probably because locusts most commonly enter Egypt from the south, being bred in Nubia or Abyssinia; but the Hebrew (ruakh kddim) is undoubtedly an east wind; and modern travellers tell us that this is a direction from which locusts arrive in Egypt occasionally (Denon, Voyages en Egypte, p. 286). In such cases they are bred in Northern Arabia.