The End and the Beginning
Even though Yaakov's "zevachim" may be a thanksgiving offering, he is still be worried about the implications of his departure from Eretz Canaan.
However, God's response to Yaakov's offering adds an entirely new dimension to this departure, a dimension that most likely catches Yaakov totally by surprise:
"Then God spoke to Yisrael ... Fear not to go down to Egypt, for I will make you there a great nation. I Myself will go down with you ... and I Myself will also bring you back..." (46:2-4)Yaakov, we explained, may have been planning only a 'short visit' to reunite the family. Yosef was planning for the family to stay for several years to survive the famine. Now, God reveals a totally new plan. Yaakov and family are departing on a journey of several hundred years. They will not return until they have first become a great nation in the land of Egypt! God Himself brings them down, and there they must remain until they emerge as a populous nation. Ultimately, God Himself will bring them back.
Hence, when Yaakov goes down to Egypt, not only will the prophetic dreams of Yosef be fulfilled, but so will God's promise to Avraham Avinu at Brit Bein Ha'btarim - the long and difficult process of Yetziat Mitzrayim (see Breishit 15:13-18).
Thus, God informs Yaakov that although his descent to Egypt involves leaving Eretz Canaan, it does not constitute a breach of the Divine covenant with his family. Rather, it forms a critical stage in His master plan of transforming Yaakov's family of 'seventy souls' into God's special Nation.
[The fuller meaning of this final "hitgalut" of Sefer Breishit will be discussed in our introductory shiur to Sefer Shmot.]