Charles Ellicott Commentary Exodus 5:3

"And they said, The God of the Hebrews hath met with us: let us go, we pray thee, three days` journey into the wilderness, and sacrifice unto Jehovah our God, lest he fall upon us with pestilence, or with the sword." — Exodus 5:3 (ASV)

The God of the Hebrews. —Moses accepts Pharaoh’s view, and does not insist on the authority of Jehovah over Egyptians, but makes an appeal ad misericordiam. He has, at any rate, authority over Hebrews; and, having made a requirement, He will be angered if they neglect it. Will not Pharaoh allow them to escape His anger?

With the sword. —Egypt was very open to invasion on its eastern frontier; and the brunt of an invasion in this quarter would fall upon the Hebrews. In the time of the nineteenth dynasty, Hittite incursions were especially feared.