Exodus 10 - God's hardening of Pharaoh's heart is to show power over Egypt's gods. Pharaoh's officials try to convince him to let the Israelites leave. The plagues of locusts and darkness are sent and Pharaoh still refuses to let the people go on God's terms. He rejects Moses and warns against his coming back.
Exodus 11 - Moses' final word to Pharaoh is to warn of the death of the firstborn throughout Egypt. He then leaves Pharaoh in great anger. Pharaoh has nobody to blame but his own stubbornness and rebellion against the God of Israel.
Exodus 12 - God gives instructions to Moses on preparing the Passover meal and applying the lambs' blood on the door sills and lintels to protect the families from the judgment to fall on Egypt. He also gives instruction on the Passover celebrations and the Feast of Unleavened Bread for future generations. Israel is always to remember this night of salvation!