Exodus 10:20-22

New Revised Standard Version, Anglicised Catholic Edition

²⁰ But the Lord hardened Pharaoh’s heart, and he would not let the Israelites go.

The Ninth Plague: Darkness

²¹ Then the Lord said to Moses, ‘Stretch out your hand towards heaven so that there may be darkness over the land of Egypt, a darkness that can be felt.’ ²² So Moses stretched out his hand towards heaven, and there was dense darkness in all the land of Egypt for three days.