What is this plague doing here? It seems out of sequence. Thus far there have been eight plagues, and they have become steadily, inexorably, more serious. The first two, the Nile turning blood red and the infestation of frogs, seemed more like omens than anything else. The third (lice) and fourth (wild animals) caused discomfort, not crisis. The fifth, the plague that killed livestock, affected animals, not human beings.
The sixth, boils, was again a discomfort, but a serious one – no longer an external nuisance but a bodily affliction. (Remember that Job lost everything he had, but did not start cursing his fate until his body was covered with sores: Job 2.) The seventh and eighth, hail and locusts, destroyed the Egyptian grain. Now there was no food. Still to come was the tenth plague, the death of the firstborn, in retribution for Pharaoh’s murder of Israelite children. It would be this that eventually broke Pharaoh’s resolve.
So we would expect the ninth plague to be very serious indeed, something that threatened, even if it did not immediately take, human life. Instead we read what seems like an anticlimax:
Then the Lord said to Moses, “Stretch out your hand toward the sky so that darkness will spread over Egypt – darkness that can be felt.” So Moses stretched out his hand toward the sky, and total darkness covered all Egypt for three days. No one could see anyone else or leave his place for three days. Yet all the Israelites had light in the places where they lived (10:21-22).
Darkness is a nuisance, but no more. The phrase “darkness that can be felt” suggests what happened: It was a khamsin, a sandstorm of a kind not unfamiliar in Egypt that can last for several days producing sand- and dust-filled air that obliterates the light of the sun. A khamsin is usually produced by a southern wind that blows into Egypt from the Sahara desert. The worst sandstorm is usually the first of the season, in March. This fits the dating of the plague that happened shortly before the death of the firstborn, on Pesach.
The ninth plague was a miracle, but not an event wholly unknown to the Egyptians – then or now. Why then does it figure in the narrative, immediately prior to its climax?
The answer lies in a line from Dayeinu, the song we sing as part of the Haggadah: “If G-d had executed judgment against them [the Egyptians] but had not done so against their gods, it would have been sufficient.” Twice the Torah itself refers to this dimension of the plagues:
“I will pass through Egypt on that night, and I will kill every firstborn in Egypt, man and animal. I will perform acts of judgment against all the gods of Egypt. I [alone] am G-d” (Exodus 12:12).
The Egyptians were burying all their firstborn, struck down by the Lord; and against their gods, the Lord had executed judgment (Numbers 33:4).
Not all the plagues were directed, in the first instance, against the Egyptians. Some were directed against things they worshipped as gods. That is the case in the first two plagues. The Nile was personified in ancient Egypt as the god Hapi. Offerings were made to it at times of inundation. The inundations themselves were attributed to one of the major Egyptian deities, Osiris. The plague of frogs would have been associated by the Egyptians with Heket, the goddess who was believed to attend births as a midwife, and who was depicted as a woman with the head of a frog.
These symbolisms, often lost on us, would have been immediately apparent to the Egyptians. Two things now become clear. The first is why the Egyptian magicians declared, “This is the finger of G-d” (Exodus 8:15), only after the third plague, lice. The first two plagues would not have surprised them at all. They would have understood them as the work of Egyptian deities who, they believed, were sometimes angry with the people and took their revenge.