Exodus 10:21-23 NIV

[21] Then the LORD said to Moses, “Stretch out your hand toward the sky so that darkness spreads over Egypt—darkness that can be felt.” [22] So Moses stretched out his hand toward the sky, and total darkness covered all Egypt for three days. [23] No one could see anyone else or move about for three days. Yet all the Israelites had light in the places where they lived.