The Abravanel on Yom HaKippurim

 I came across a fascinating Abravanel on the topic of fasting and affliction on yom kippur, so I want to share it (bold is mine).

“And here, the benefit of the fast and of abstaining from creative work on this sanctified day is clear, because through this, the soul isolates itself [from physicality] to cling to Hashem. When our physicality - which desires transient things - weakens, our craving for the permanent things, which is the mind, will become stronger. 

And the mekubalim already mentioned that there is a higher power that comes down to consume the offering, and that is the fire that descends upon the altar. And in parallel, in the lower realm there is in man his bones that will consume his fat and his blood 
 and that is his life energy. And therefore, we have been commanded that a person should direct his spirit and his soul on the fast day, as if he is the altar for atonement in which his fat and his blood are being burnt for the service of his creator. And they [the chachamim] established that a person should say in his self affliction (of fasting and abstinence of all physical pleasures): "may it be G-ds will that it will be considered that my fat and my blood serve as the offering" etc… And in Midrash Rut it is said that rabbi Nechunia, the son of Hakaniya, said to the chachamim: my son - [I swear by] your life that there is no sacrifice more desirable before G-d than the heart of a person that burns in his fast.” 

Observations 

1) Fasting and affliction should make us quickly realize how frail we are. It is remarkable how quickly our bodies become weak and our minds can barely function when we have only been fasting for a day. It should also make us realize how ephemeral and temporary our physical world is, when within hours, our body starts to decay. This experience should help us detach ourselves from all of our attachment to the physical world and instead attach ourselves to actual reality: G-d and His wisdom. 

 I’m curious how many people are able to come to this realization in their state of fasting. 

2) It is definitely emotional striking to imagine yom kippur as a day of burning our bodies as a sacrifice through our fasting. But what exactly is this idea supposed to convey? 

Maybe it’s not just that our desires for the physical that draw us to things that are ephemeral, fragile, and ultimately meaningless, but more importantly it is our egos. Our egos causes to chase honors, successes, satisfactions that are actually empty.

There is something jarring to the ego about a sacrifice of our own bodies. We are basically proclaiming that we don’t matter; our bodies can be burned for some purpose outside of ourselves. The point of "sacrificing ourselves" is to withdraw our focus from our own egos so that we can direct our energies towards G-d.