As for you, you meant evil against me, but God meant it for good in order to bring about this present result, to preserve many people alive. (Gen 50:20, NASB)
This verse is perhaps the strongest verse used by Calvinists to support the concept of compatibilism. To quote a contemporary apologist for Calvinism who appeals to this text:
These are the words of one who has come to see the sovereign plan of God in his own life. Joseph well knew the motivations of his brothers when they sold him into slavery. But, in the very same event he saw the over-riding hand of God, guiding, directing, and ultimately meaning in the same action to bring about good. (James R. White, The Potter’s Freedom: A Defense of the Reformation and a Rebuttal to Norman Geisler’s Chosen but Free [2d ed.; Calvary Press, 2009], 48)
There are a couple of important considerations that cast doubt onto the popular Reformed reading of this verse.
Firstly, the Joseph narrative in Genesis clearly ascribes the responsibility for selling Joseph into Egypt onto his brothers, and there is no mention of this being part of the “secret decree” of God:
Then there passed by the Midianites merchantmen; and they drew and lifted up Joseph out of the pit, and sold Joseph to the Ishmeelites for twenty pieces of silver: and they brought Joseph into Egypt. (Gen 37:28)
And Joseph said unto his brethren, Come near to me, I pray you. And they came near. And he said, I am Joseph, your brother, who ye sold into Egypt. Now therefore be not grieved, nor angry with yourselves that ye sold me hither for God did send me before you to preserve life. (Gen 45:4-5)
While some may appeal to the above text in Gen 45 as further evidence in favour compatibilism, Joseph tells his brothers that they committed evil in selling him and sinned against him (Gen 42:22). Only by presenting God as the author of sin can a Calvinist appeal to such an interpretation of this pericope.
Further, in suggesting what they intended for evil God intended for good, Joseph speaks to his brethren in a form of poetical parallelism, so should be understood as a rhetorical flourish, not the basis for systematic theology. The Hebrew reads:
וְאַתֶּם חֲשַׁבְתֶּם עָלַי רָעָה אֱלֹהִים חֲשָׁבָהּ לְטֹבָה לְמַעַן עֲשֹׂה כַּיּוֹם הַזֶּה לְהַחֲיֹת עַם־רָב
The Hebrew is captured rather well in the 1985 JPS Tanakh:
Besides, although you intended me harm, God intended it for good, so as to bring about the present result--the survival of many people.
The Hebrew verb translated as "to intend" is חשׁב (to think/reckon/credit/assume). Commenting on this verse and the theology of the Joseph in Egypt narrative vis-à-vis human freedom and foreknowledge, John Sanders wrote:
How should Joseph’s remarks that God “sent” him to Egypt and made him ruler of Egypt (Gen 45:5, 7, 9) be understood? First, it should be remembered that Joseph has used language like this before. In Genesis 43:23 he says that God gave the money back to his brothers even though Joseph admits that he had the money put in their sacks (see Gen 42:25, 28). Furthermore, the remarks of Gen 45:5, 7, 9 occur at a tense moment in the dialogue. Joseph’s brothers are overwhelmed by anxiety, and they fear for their lives due to the ruse Joseph has played on them. Moreover, Joseph is brought to tears in the presence of his brothers, desiring reconciliation. Now is not the time for condemning words. He desires to vanquish his brother’s fears. Although he acknowledges that they sold him into Egypt, he suggests that everyone look on the bright side—what God has done through this. Their lives and those of the Egyptians have been spared the devastating effects of the famine.
Joseph plays down the human factor and elevates the divine factor in order to allay their fears. After reconciliation is assured, Joseph remarks that what they intended for evil, God intended for good, so that many people would live (Gen 50:20). It is the glory of God to be able to bring good out of evil human actions. But nothing in the text demands the interpretation that God actually desired the sinful acts. The text does not say that God determined the events. In fact, the text is remarkably silent regarding any divine activity until Joseph’s speeches. Until now, the events could have been narrated without reference to divine activity at all. In fact, unlike in the other patriarchal stories, here God is strangely absent. Joseph never invokes God! It is in retrospect that Joseph identifies God’s activity in his life, and his words require the interpretation that God exercises meticulous control over human affairs. (John Sanders, The God Who Risks: A Theology of Divine Providence [2d ed.; Downers Grove, Illin.: IVP Academic, 2007], 85)
Another consideration adding support to Sander’s claim that Joseph “desires to vanquish his brother’s fears” is found in Gen 45:3
And Joseph said unto his brethren, I am Joseph; doth my father yet live? And his brethren could not answer, for they were troubled at his presence.
The Hebrew term the KJV translates as “troubled” is בהל which means "to be terrified, out of one's senses" (cf. Exo 15:15).
Gregory Boyd points out the theological difficulties resulting from the traditional way Calvinists absolutistise Gen 50:20:
[I]f we interpret this episode as evidence of how God always operates, we must accept the consequence that this passage always minimizes the responsibility of human agents. This is the conclusion Joseph himself draws from his observation that God used his brothers to send him to Egypt. “Do not be distressed, or angry with yourselves,” he tells them, “for God sent me.” If this text is taken as evidence of how God always controls human action—if God is involved in each kidnapping and murder the way he was involved in the activity of Joseph’s brothers—we must be willing to console every murderer and kidnapper with Joseph’s words: “Do not be distressed or angry with yourself, for God kidnapped and murdered your victims.” We cannot universalize the mode of God’s operation in this passage without also universalizing its implications for human responsibility. No one, of course, is willing to do this. (Gregory A. Boyd, Satan and the Problem of Evil: Constructing a Trinitarian Warfare Theodicy [Downers Grove, Illin.: IVP Academic, 2001], 396-97)
Additionally, Boyd notes that:
The text only suggests that at some point in the course of God’s interaction with humans, God decided that it fit his sovereign purpose to steer the brothers’ intentions in the manner we read in Genesis. It wasn’t God’s original plan that the brothers would acquire the character they did, but in the flow of history it fit his plan to use these brothers in the way he did. (Ibid., 397)
As we have seen, there are a number of problems with the common Reformed appeal to Gen 50:20 as biblical evidence in favour of compatibilism.