But the Lord replied to Moses, ‘Now you will see what I will do to Pharaoh: because of a strong hand he will let them go, and because of a strong hand he will drive them from his land.’
The Lord instructed Moses, ‘When you go back to Egypt, make sure you do before Pharaoh all the wonders that I have put within your power. But I will harden his heart , so that he won’t let the people go.
Pharaoh sent messengers who saw that not a single one of the Israelite livestock was dead. But Pharaoh’s heart was hard, and he did not let the people go.
When Pharaoh stubbornly refused to let us go, the Lord killed every firstborn male in the land of Egypt, both the firstborn of humans and the firstborn of livestock. That is why I sacrifice to the Lord all the firstborn of the womb that are males, but I redeem all the firstborn of my sons.”