Adonai said to Moses, “Now you will see what I am going to do to Pharaoh. By way of a strong hand he will let them go, and drive them out of his land.”
Adonai said to Moses, “When you go back to Egypt, see that you do all the wonders before Pharaoh that I have put in your hand. Still, I will harden his heart, and he will not let the people go.
When Pharaoh inquired, there was not so much as one of the cattle of Bnei-Yisrael dead. But the heart of Pharaoh was stubborn, and he did not let the people go.
and when Pharaoh refused to let us go, Adonai slew all the firstborn in the land of Egypt, both men and animals. So I sacrifice to Adonai all firstborn males, but I redeem the firstborn of my sons.’