The Sfas Emes blog
וירא בלק ... את כל אשר עשה ישראל לאמורי: ויגר מואב מפני העם מאד כי רב הוא .../Balak … saw everything that Israel did to the Emorites. Moav was very afraid of the people for they were many …" (Bamidbar 22:2,3) Why was Moav afraid? The nation of Israel had no designs on Moav's land. Israel even acquiesced to Moav's request that the people not traverse Moav in order to enter Cana'an.
Balak and Moav were not concerned that Israel would conquer their land. They were concerned about something far deeper. We can learn what was bothering Balak from the Zohar's explanation of a pasuk in Tehillim (31:20), "מה רב טובך אשר צפנת ליראיך .../How great is the good that You have hidden for those who are in awe of You …"
What is the "good" that God has hidden for the righteous and where did He hide it? The Zohar teaches that the good is the first light that God created, "וירא א-להים את האור כי טוב/God saw that the light was good." (Breishis 1:4) The Zohar says that this first light was not the physical light that we see today. The physical light of today comes from the celestial bodies and from fire in all its forms. The first light must have been something else since it was created before the celestial bodies and before fire. Rather, the first light may be better understood as enlightenment. It was the enlightenment that came from the Torah which God used to create the world and which is hidden within the works of the Creation.
Chazal teach us that the pasuk, "וירא א-להים את כל אשר עשה והנה טוב מאד/God saw everything that He did and behold it was very good," (Breishis 1:31) refers to the angel of death and the evil inclination. How so? The angel of death and evil inclination represent God's concealment in the physical world. They represent the concealment of the hidden light of the Torah. God saw that everything He made was very good because the light of the Torah, which was referred to before as "good" was hidden in everything that God had made.
While there will come a time when God, according to His Divine plan will reveal the hidden light, our mission is to find that hidden light now. The result is a revelation of the undeniable truth. In this way we can influence our surroundings to become subordinate to God. The children of Israel as they sojourned in the desert experienced the hidden light all the time. They lived with daily miracles. The effect on their surroundings was dramatic.
Balak was unavoidably affected as well. "וירא בלק .../Balak saw" that God's glory was revealed, "ואמרו אל יושב הארץ הזאת ... אשר עין בעין נראה אתה .../They will say about the inhabitants of this land … that God appears to them eye to eye …" (Bamidbar 14:14) This revelation of holiness totally contradicted Balak's view of reality. In fact, Balak refers to this when he says, "... עם יצא ממצרים הנה כסה את עין הארץ .../… a nation left Egypt; behold it covered the face (lit. eye) of the land …" (Bamidbar 22:5) ארץ/Land represents nature. It represents Balak's view of reality. He considered the holiness to which he was exposed as covering up his own eyes so that he could not see reality clearly. This is the exact opposite of the truth.
Balak saw this and was afraid. He was afraid of the aspect of "hidden light" represented by מאד/very in the pasuk, a reference to the hidden light which is described in the story of the Creation as "very good". The nation of Israel caused him to be exposed to the hidden light. The words, "כי רב הוא/for they (the people of Israel) are many," is a reference to, "מה רב טובך/How great is your good (i.e. the hidden light)."
According to the Sfas Emes, Balak saw the revelation of God's glory. He was unable to assimilate the holiness and was therefore afraid. It totally contradicted his view of reality.
The nation's sojourn in the desert, then, was an important preparatory period for the nation before entering the land of Israel. It was during this period that the notion of the hidden light became totally ingrained and internalized in the national psyche.
The land of Israel, according to the Zohar is the center point of the entire world. The very force that causes the entire Creation to exist comes first from this center point and sustains all. Experiencing and being exposed to the hidden light was thus crucial to being able to benefit fully from life in the land of Israel.
 Viz. Shoftim 11:17
 Zohar 3:88a
 Zohar 1:5a Introduction
 Breishis R. 9:7,10
 Zohar 1:108b