Once again, we need to ask what was Avraham's destination? To which 'south' was he going?
Rashi: The south refers to Har ha'Moriyah (which was situated in the south of Eretz Yisrael), as Rahi explained above, in chapter 12, Pasuk 9).
Refer to 12:9:11**. The question that we asked there (why Avraham never seemed to arrive there) is compounded, since just two Pesukim later, the Torah informs us that he changed his itinerary.
Why does the Torah see fit to mention that Avraham left Egypt with all his possesions?
Ramban: This tells us that despite the fact that Sarah did not become queen of Egypt (the objective of all the gifts that Pharaoh gave Avraham), they did not accuse Avraham of having cheated them, and demand that he return them.
In fact, says the Ramban, this was a miracle.