Gemara:


Ein Ayah: The image that is described has an eternal message. Bravery is indeed a nice tool, and it is very necessary for a nation that lives and performs important acts for itself and others in the world. However, the power a nation needs to display is not a power that is so physical that it strangles spiritual powers. Rather, such physical power should fall before the grandeur of spirituality. The proper type of power is that which gives strength to the power of the spirit and to wisdom. It is very appropriate for the spiritual power to support the pure spirit and "raise the person’s heart in the ways of Hashem" (based on Divrei Hayamim II, 17:6).
One cannot compare the physical prowess of a Moshe Rabbeinu to the awe-inspiring giant, Og. Yet, Moshe was able to overcome Og, with a touch of pure bravery, which comes from the power of a healthy and pure spirit in a healthy and pure body. That is enough to conquer the material strength so that it will not be able to rise up again.
When someone whose strength is spiritual needs to conquer someone of great physical strength, he will naturally use his great intellect in choosing a useful weapon. He also is likely not to be weighed down by animalistic denseness, but will be light in his ability to elevate himself in intellectual and ethical matters. The metaphor, in the physical realm, for this lightness is the ability of Moshe to jump ten cubits. Thus, Moshe even though he was strong, as befits a prophet (Shabbat 92a), was not so massive that his body or his spirit could not soar. His ability to jump ten cubits was a significant physical feat. However, it was no less an expression of a spiritual strength, enabling him to rise to the lofty calling that can be achieved when Israel is victorious. It suffices for a small strike of physical strength (i.e., hitting in the ankle), when it comes from a giant in spirituality, to destroy a giant of physical strength. This is reminiscent of the fall of the giant statue in the dream of Daniel, when it was struck in the leg and destroyed (Daniel 2:34).
Moshe’s victory is a case of an action by the forefathers that stands as an omen for future generations, as the voice of Yaakov will overcome the overly material hands of Eisav. As the p’sukim say: "Hashem will give valor to His nation" (Tehillim 29:11); "He will give valor to His king and raise the stature (literally, horn) of His anointed one" (Shmuel I, 2:10). The spiritual power of Israel will only touch lightly the material power related to idolatry, which proclaims, "I am it, and nothing else exists." Indeed idolatry has ceased from the better part of mankind, based on a mere touch by Moshe Rabbeinu. The spirituality that has come from the springs of Israel has made great progress, and will culminate eventually when Mashiach comes with the "the staff of his mouth and the spirit of his lips" (Yeshaya 11:4) to bring both salvation and the end of evil.