The passover and departure of the Israelites.
It’s all about the nature of God. He’s above all other god’s. The plagues have systematically shown his power over the gods of Egypt.
He’s a God of judgement. He decides the time of our death. So the Egyptians lost the first of their families and livestock.
He’s a god who chooses. The Israelites are separated by passover and by circumscision.
He’s a god who rescues, setting an enslaved people free.
The God of the Messiah, the one I pray to every day.