כ' דור תהפוכות הנה Ha' azinu 32.20
This passuk is a critique about Klall Yiroels' unreliability and how we may reverse good will from Hashem to become anger חס ושלום.
The sifri says that we are הפכפכים - moody. Similar to the gamara's description of Achashveirosh. We make commitments on Yom Kippur, but often, quite soon after, the mood of Yomim Noraim dissipates and we are Overcome with other thoughts & feelings that seem to render our pure intentions of Yom Kippur useless. דור תהפוכות
(This may be another reference point of Yom Kippurim) -
How lucky we are thatwe are judged according to the good intentions a that day באשר הוא שם!
However dismal as it seems, not all is lost. The esrog has a message For Us about these commitments. Rav Brudny shlitah spoke for KollelH a few years ago and said as unrecognizable as the effects of Yom Kippur may be, they are actually there to remain.
Like one who enters a perfume shop, he exits with some of the wonderful Scent upon him, so too, a Yid who experiences Yom Kippur properly, exits as a different Yid.
There is an indescernable change and purity that remains with any Yid who "does" Yom Kippur.
Perhaps this is hinted to in the Esrog. The most important part of an Esrog is called the "chotem" - the nose. Hinting that we must ensure that at least the scent of Yom Kippur remains with us.
The two primary signs of an authentic esrog are it bumps and it's עוקץ - root - that must be sunken in.
Perhaps our commitment was a bit too bold עז כנמר and it may have ups and downs throughout the year- but the עוקץ - anchor - how we connect back to our good shoresh, must be sunken in, deep inside so at least the aroma, the essence of Yom Kippur has a lasting effect.
Perhaps a small Kabbalah that is easy, light, - perhaps almost indescernable! -
that is anchored so well that it wont be subject to failure (if the עוקץ) falls out
the esrog is passull) that keeps the lingering scent of Yom Kippur.
Another hint may be the horizontal seeds alluding to the קבלות that are full of future potential, yet they are "low lying" compared to other fruit. Again עז כנמר קל כנשר.