There is a syntactical irregularity in the verse that records this exchange: "And Joseph's brothers saw that their father had died, and they said, 'Lest (lu) Joseph will hate us and repay us all of the evil that we have done him.' And they sent to Joseph saying, 'Your father commanded before his death...'" (Genesis 50:15-16).
The medieval commentator Rashi notes that elsewhere in the Bible, the word "lu" always means either "if only" or "perhaps." Here, though, "lu" must mean "lest." Otherwise, the verse would read, "If only Joseph would hate us," and surely Joseph's brothers do not want him to hate them. They go to great lengths to convince Joseph that their father had asked for forgiveness for them.
An alternate reading of the verses, though, could suggest that the brothers are feeling conflicted. Certainly, a part of them wants good treatment and absolution from Joseph. I would argue, though, that another part of them wants Joseph to hate them. In order to understand how this could be, we must look back at the history of the relationship between Joseph and his brothers.
In Chapter 37, overcome by jealousy and rage, the brothers throw Joseph into a pit and sell him as a slave. The brothers return home to face their father's tormented anguish over the loss of Joseph, and for 22 years they walk around with a crippling burden of guilt.
Their abuse of Joseph weighs heavily on them, and they interpreted even apparently unrelated events through the lens of their culpability. When the viceroy of Egypt--a disguised Joseph--treats them harshly and accuses them of spying, the brothers begin to talk about their home life and about the brother who is missing.
Joseph tries to make it better for them. When he reveals himself to them, he offers them forgiveness. He tells them it was God's will that he come to Egypt. He promises them food and support. He kisses them all and cries on them, but they can barely speak to him. They are too imprisoned by their own guilt to be able to reconcile. They cannot accept Joseph's forgiveness because they cannot forgive themselves.
And so, in our portion, when Jacob dies, what the brothers are saying in part is "if only Joseph will hate us and repay the evil we did him." If only Joseph could avenge himself and give us back the wrong we did him, then perhaps we could finally be at peace. It is a complex moment, with their instinct for self-preservation mixing with their desire for ultimate absolution. They both want Joseph's hatred and yet need his protection.
But Joseph does not crave revenge. All he yearns for is reunion with his family. He has spent 22 lonely years, and now he wants his brothers back. He will give them everything--forgiveness, sustenance, vocations, even riches--and all he wants in return is once more to be part of the family.
The book of Genesis ends with Joseph asking his brothers to take his bones with them when they eventually leave Egypt. He must ask them to do this because he does not believe they would think to do it on their own. Even on his deathbed, Joseph knows that his brothers do not really think of him as one of the family.
The last words of Genesis tell us that Joseph's body has been placed in a coffin in Egypt. There he waits until the book of Exodus, where he will discover a reconciliation in death that he could not achieve in life.