Who is the Lord? — Heb., Who is Jehovah? If Jehovah was a name, the use of which had been laid aside, as would seem to have been the case by the later Chapter s of Genesis, and which was revived by the scene at the burning bush, Pharaoh may very probably not have heard of it.
That I should obey his voice. — The king means to say, that, whoever Jehovah is, He can have no authority over him, as He is not one of his gods. The Egyptians were accustomed to the idea of local gods, and quite expected every nation to have a deity or several deities of its own; but they regarded the power of each as circumscribed, certainly not extending beyond the race or nation to which the god belonged.