Exodus 10:20-22

Revised Standard Version

²⁰ But the Lord hardened Pharaoh’s heart, and he did not let the children of Israel go.

The Ninth Plague: Darkness

²¹ Then the Lord said to Moses, “Stretch out your hand toward heaven that there may be darkness over the land of Egypt, a darkness to be felt.” ²² So Moses stretched out his hand toward heaven, and there was thick darkness in all the land of Egypt three days;