No suffering, whether it’s pain, discipline, trials, or pursecution, is left unused by God for his greater purposes.
Over and over God chooses to bless one and not the other, or to bless one more than others. Sometimes, as with Joseph, it may be because of his faithful obedience. Other times, as with Jacob and Esau, it is before either of them are born. Either way, this book repeatedly shows that God has the right to give and take away, to bless and to curse, and no one can question this right. He is God; there is no other. See Romans 9 Commentary.
This is demonstrated in God’s calling of Abraham, his choice of Isaac over Ishmael, Jacob over Esau, Joseph over Reuben, and Ephraim over Manasseh.
This is evident as God reiterates his promise to Abraham’s descendents Isaac and Jacob. God’s first promise, the promise of the snake-crushing seed of the woman, is woven into his promises to each of the patriarchs. It is through this single descendent of Abraham, Jesus Christ, that all familes (ethnos, meaning people-groups) will be blessed. Genesis explains how the natian of Israel was birthed and it’s purpose in redemptive history.