 That's God's personal name. And so he says to Pharaoh, thus says Yahweh, let my people go. And Pharaoh says, I know not Yahweh. I don't know who Yahweh is. Who is Yahweh that I should obey his voice? I do not know Yahweh. Neither shall I let his people go. And the Lord said, no doubt in his heart, oh.