When Pharaoh was too stubborn to let us go, the Lord killed every firstborn male in Egypt—human and animal. This is why we sacrifice every firstborn male to the Lord and buy every firstborn son back from the Lord.’
The Lord said to Moses, “When you get back to Egypt, see that you show Pharaoh all the amazing things that I have given you the power to do. But I will make him stubborn so that he will not let the people go.
Then the Lord said to Moses, “Now you will see what I will do to Pharaoh. I will show him my power, and he will let my people go. I will show him my power, and he will throw them out of his country.”