The writer’s emphasis on the “good” and “bad” represents Joseph’s wisdom and discernment as an ability to distinguish between the “good” (ṭôb) and the “bad” (raʿ). Such a picture suggests that in the story of Joseph the writer is returning to one of the central themes of the beginning of the book, the knowledge of “good” (ṭôb) and “bad” (raʿ). Joseph, one who has wisdom, is able to discern between “good and bad.” It is also clear from this story that ultimately such knowledge comes only from God (v. 39). Joseph is the embodiment of the ideal that true wisdom, the ability to discern between “good and bad,” comes only from God. Thus the lesson of the early chapters of Genesis is artfully repeated in the last chapters of Genesis.
John H. Sailhamer, “Genesis,” in The Expositor’s Bible Commentary: Genesis–Leviticus, Revised Edition, ed. Tremper Longman III and David E. Garland, vol. 1 (Grand Rapids: Zondervan, 2008), 286.