Ephraem the Syrian
The angel removed the cloud that had been guiding the Israelites and positioned it between the Hebrew people and the Egyptians. When the cloud, which provided shade during the day, was set in place at night between the two groups, it plunged the Egyptians into a darkness reminiscent of the three days of darkness they had previously experienced. For the Israelites, however, there was illumination from the pillar of fire that guided them. This occurrence was meant to instill fear in the Egyptians while offering reassurance to the Hebrews. Had the Egyptians noticed this darkness, they would have refrained from entering the sea.