Yahweh tells Moses that if Pharaoh refuses to let the Hebrews go to say to Pharaoh "Thus says Yahweh: Israel is my son, my first-born and I have said to you: Let my son go, that he may serve me, and you have refused to let him go. Behold, I will slay your son, your first-born". Moses returns to Egypt and tells Pharaoh that he must let the Hebrew slaves go free. Pharaoh refuses and Yahweh strikes the Egyptians with a series of horrific plagues, wonders, and catastrophes, after which Pharaoh relents and banishes the Hebrews from Egypt. Moses leads the Israelites out of bondage toward the Red Sea, but Pharaoh changes his mind and arises to massacre the fleeing Hebrews. Pharaoh finds them by the sea shore and attempts to drive them into the ocean with his chariots and drown them.