The plague of darkness in Exodus chapter 10 is three days of impenetrable blackness across Egypt. The Hebrew Bible says simply that no one could see anyone else and no one rose from their place (Exodus 10:23). The Targum Jonathan reveals what was actually happening during those three days—and it involves Israel, not Egypt.
The Targum explains that God gave the Israelites light during the darkness for two reasons: "that the wicked among them who died might be buried, and that the righteous might be occupied with the precepts of the law in their dwellings." Not all of Israel was righteous. Some Israelites died during the plague of darkness, and the light allowed their bodies to be quietly buried without the Egyptians knowing. The darkness was not just punishment for Egypt. It was a cover for Israel's own losses—a divine act of concealment that protected the nation's dignity.
The plague of locusts, earlier in the chapter, also receives Targum additions. When the locusts are swept into the Sea of Reeds by a western wind, the Targum adds an astonishing detail: "And even such as had been salted in vessels for needed food, those too the western wind bare away." The Egyptians had captured and preserved locusts as emergency rations. God's wind was so thorough that it removed even the pickled locusts from their jars. Nothing—not even the resourcefulness of desperate people—could circumvent divine will.
The chapter ends with Pharaoh threatening Moses with death if he ever appears again. The Hebrew text has Moses simply agree: "I will see thy face no more." But the Targum's Moses delivers a final warning that reaches back to an earlier prophecy: "While I was dwelling in Midian, it was told me in a word from before the Lord, that the men who had sought to kill me had fallen from their means and were reckoned with the dead. At the end there will be no mercy upon thee." Moses reminds Pharaoh that God has already destroyed Moses's enemies once before. Pharaoh will be next.