"...However, with the uncleanliness concerning the contamination of the Land of Israel, the Torah is referring to a type of contamination that is entirely spiritual. When there is sin in the land, the land itself becomes spiritually unclean. This means that such things as seeing the spiritual perspective and learning Torah will become much more difficult than when the land was pure. In such a place, it will seem that God is hiding more. Good deeds will become rare, and kindness will all but disappear..."Then I remembered what I had just learned in the Hesed L'Avraham. Rav Azulai explains that the land of Israel is protected entirely from the influence of the other side by a shell that surrounds it. God never lets the outer forces breach this barrier and enter the land except when a person chooses to let these forces in by using his own free will to sin. Because HaShem gives us complete free will, we have the ability to bring these dark influences even into the land of Israel which HaShem constantly protects from such influences.