Moses having an intimation from the Lord that one plague more would be brought on Pharaoh, and then he would let Israel go, when they should borrow of their neighbours jewels of gold and silver, the people being in great favour with the Egyptians, Ex 11:1-3, he declares to Pharaoh, before he went out of his presence, the slaying of all the firstborn in Egypt, which would issue in the dismission of Israel, and then he went out from him in great anger, Ex 11:4-8, but still Pharaoh would not hearken, and his heart was hardened, and he refused again to let Israel go, Ex 10:9,10.