It's All Hevel

On Succos we offer seventy bulls corresponding to the seventy nations of the world. These korbanos both help fix the nations and protect us from their evil schemes [and with that רשע from Iran we need it]. It behooves us therefore to learn the perek of tehillim that talks about the goyim's praising of Hashem. [It is the shortest perek in all of Tanach.]

הללו את הוי' כל גוים, שבחוהו כל האמים, כי גבר עלינו חסדו ואמת הוי' לעולם הללויה  - Praise Hashem all of the nations, praise Him all of the states. For His kindness has overwhelmed us and the truth of Hashem is eternal, Halleyuyah. 

There are 17 words, טוב in gematria, [according to the tradition that הללו יה are two separate words] and 62 letters, טוב מאד in gematria. טוב מאד is identified by Chazal as the connection between the yetzer hara and yetzer tov, the Angel of Life and the Angel Of Death, gan eden and gehenom, it can also be identified with the Jews and the nations of the world who praise Hashem for His salvation.

The perek is 62 times the gematria of the word הבל  - vanity or hot air [36]. That means that since there are 62 letters the average of each letter is gematria  הבל. On Succos we deal with the הבל in this world by reading קהלת and הבל is also the hot air that comes out of our mouth when we [and the nations] praise Hashem. We thus reveal the highest level of the soul - called יחידה, which of course is same gematria - 36. By connecting to the yechida of our souls on Rosh Hashana and Yom Kippur, we are ready on Succos to reveal the יחידה of the nations of the world.

[Based on a shiur by Rabbi Yitzchak Ginzburg Shlita].