(Devarim Rabbah 11:10). But what kind of a kiss was that? The soul of Moshe was forced to leave. Is that love?
When someone bestows good on another, the recipient has a debt of gratitude. In fact, he owes him everything, except for the gift itself. Let’s say someone gifts his friend with a $10 pen. The next day, he asks him for a loan of $10,000. Gratitude obligates the recipient to grant the loan. But if the giver asks for the pen itself, the recipient doesn’t have to give it back to him. The recipient owes him everything, but not the pen.
Moshe’s soul didn’t want to leave, and it didn’t have to, because you can’t force someone to give back a gift. So Hashem said, so to speak: You’re right, you don’t have to give yourself to Me. I am asking you to give Me a gift. This was communicated through a “kiss.” A kiss on the mouth is a mutual expression of love which is both given and received simultaneously. Thus, Moshe returned his soul to Hashem through a “kiss” of total love and devotion to Hashem.
Hoshana Rabba is a day of kisses. We “kiss” Hashem, so to speak, meaning that we devote and give ourselves totally to Him. This mesirus nefesh doesn’t mean that we actually give up our lives. It means that we totally dedicate ourselves to serve Hashem.
Beating aravos is a minhag originating with the Nevi’im (Sukkah 44a). It is not a legally binding obligation. Aravah resembles the mouth, it represents a kiss of total devotion, and mesirus nefesh of this type is not something that you can ordain and obligate. You can’t force someone to give his very self. It is a “minhag,” meaning that it comes from deep within a person.
This may be compared to a father who told his son to do some tasks for him. After the son finished all he was told to do, he also gave his father a kiss. He was not asked to give a kiss – it came from the son himself.
On Rosh Hashanah we blew the shofar. On Yom Kippur we fasted. Then we built sukkos and dwelt in them, and took lulavim, too. After we finished all we were told to do, and we put down the lulav, and there was no more specific mitzvah we need to perform, our Jewish heart feels love and devotion for Hashem, and we give ourselves totally to Him through a kiss, through the aravos of Hoshana Rabba.
After this, Hashem kisses us back, and that is the day of Shemini Atzeres.
