Abraham, Jacob, and the Israelites in Egypt acquire wealth from foreign peoples in morally ambiguous ways. In contrast, the Judeans' return from exile, depicted as a second exodus, is accomplished with the blessing of the gentile king, and the wealth obtained in exile is entirely untainted.
From God’s first command to Moses, through the story of Israel’s escape, the demand for a three-day festival in the wilderness plays a prominent role in the plague narrative. Part of this ruse was Israel’s request to “borrow” Egyptian finery for the festival. Why does God want the Israelites to use deception?