Hashem gives the land of Eretz Yisrael to Avraham Avenu for him and his children, as a gift and inheritance forever; thus the Jews make the land Eretz Hakodesh, a holy land. This happened twice before. Once when the Jews entered the land, the first time- by conquering it . The second time by repossessing the land. This represents two ways of serving Hashem. The first is compared to the service of a Tzadik-overwhelming the darkness- but then there is no guarantee that the holiness will be permanent.

The second way is like a Bal Tshuvah, working with the darkness, elevating it and returning it to Hashem. With that type of service the holiness will remain.

לקו״ש טו