In this week's Parsha, before Yaakov blesses Menasheh and Ephraim, he says to Yosef, "And I, when I came from Paddan, Rachel died unto me in the land of Canaan... and I buried her there on the way to Efras, which is Beis Lechem" (בראשית מ"ח:ז').
The Nachalas Tzvi on this Posuk presents a number of problems. First of all, what is the meaning of the word עלי, "unto me", in this Posuk? Why didn't the Torah simply state that Rachel died in Canaan and omit the words "unto me"? Second of all, by saying "unto me", Yaakov seems to be admitting to Yosef that he was somehow directly responsible for the death of Rachel. Why was this? Finally, why does Yaakov have to state that Rachel died in the land of Canaan at all? It would have been enough to say that he buried her in Beis Lechem, which would have indicated to Yosef that she had died in Canaan.
The answer suggested there uses the idea of the Ramban who says that our forefathers kept all of the Mitzvos of the Torah only while living in Eretz Yisrael, but not when living outside the Land. The Torah forbids the marriage of a man to two sisters, but it was nevertheless permissible for Yaakov to be married to Rachel, Leah's sister, because they were living outside of Eretz Yisrael. However, once they came into Eretz Yisrael, the marriage became forbidden. Therefore, once Yaakov reached the land of Canaan, Rachel died.
This, then, is what Yaakov meant to communicate to Yosef: "And when I came from Paddan , which is outside of Eretz Yisrael, Rachel died unto me-that is, because of me. I married her after marrying her sister. Therefore, when we later travelled to the land of Canaan, where that type of marriage became forbidden to me, Rachel died."
Yaakov thus informed Yosef fully of the circumstances surrounding his mother's death.