In Breisheet 20:1 we read: "Avraham journeyed toward the Negev and dwelt (vayeshev) between Kadesh and Shur and he sojourned (vayagar) in Grar."

Grar was the land of the Plishtim (Philistines), in the vicinity of where the Gaza strip is today.

Why did Avraham travel to Grar?

At first glance, one may think that he went because of a famine. After all, in Parshat Lech Lecha Avraham went down to Egypt because of a famine in the Land of Israel. In Parshat Toldot, Breisheet 26:11, Yitzchak goes to Avimelech, King of the Plishtim in Grar because of a famine. However, our case is different. When we take a closer look at Breisheet 20:1, we see that there is no mention of a famine. Furthermore, in Parshat Toldot, Breisheet 26:11, we can infer that there was only one famine in the days of Avraham and that was the famine when Avraham went down to Egypt.

According to Radak, the reason why Avraham went to sojourn in Gerar was so that he could acquire and hold on to the entire land of Israel. He was staking his claim. As God promised Avraham in Breisheet 13:16: "Arise, walk through the land in the length of it and in the breadth of it; for I will give it to you."

Radak adds that the land of the Plishtim is considered part of the land of Israel. This can be found in Breisheet 15:21.

In the Book of Yehoshua 13:3 we find that the land of the Plishtim is included in the inheritance of the tribe of Yehudah.

We can learn from Avraham the importance of traveling throughout the Land of Israel. Traveling in Isreal shows that we care about the land and that we want to inherit it.