a Yom ha'Atzmaut not of simcha or sasson, but of chedva

R' Lerrer from Merkaz haRav said that R' Tzvi Yehudah would quote from the teshuvos Ye'shuos Malko from R' Yehoshua m'Kutna (from the likutim section in the back) on the pasuk וַיִּחַדְּ יִתְרוֹ עַל כׇּל הַטּוֹבָה.  Rashi there quotes two interpretations.  One pshat is that Yisro was overjoyed at the deliverance of Am Yisrael, which is certainly the peshuto shel mikra, as Ibn Ezra comments ויחד – מגזרת: חדוה.  But then Rashi quotes a second interpretation ומדרשו (בבלי סנהדרין צ״ד.): נעשה חידודין חדודין, מיצר על איבוד מצרים.  Why does Rashi need to quote a Midrash and throw cold water on the simcha of Yisro [this is the Mizrachi's question as well]?  Why was Rashi not happy with the peshuto shel mikra as is?  

That shoresh of ויחד -- the term חדוה -- appears in a famous pasuk that Rashbam there alludes to.  When the handful of people returned with Ezra to build Bayis Sheni, there were those among them who cried when they saw their accomplishments.  They remembered the glory of Bayis Rishon, and knew that what they had was a pale comparison.  It was to them that Ezra directed his words לְכוּ אִכְלוּ מַשְׁמַנִּים וּשְׁתוּ מַמְתַקִּים וְשִׁלְחוּ מָנוֹת לְאֵין נָכוֹן לוֹ כִּי קָדוֹשׁ הַיּוֹם לַאֲדֹנֵינוּ וְאַל תֵּעָצֵבוּ כִּי חֶדְוַת ה׳ הִיא מָעֻזְּכֶם  There are different terms for happiness, says the Ye'shuos Malko.  Simcha is the joy of a new experience; sasson is the joy of rediscovering that which had been lost.  Chedva is a different animal entirely.  Chedva is when one's heart is breaking inside, but nonetheless, one rejoices.  Sometimes joy does not come easily; a person needs to coax themselves into finding it.  

Rashi's second interpretation does not mean to say that Yisro was not happy.  Both pshatim agree in that regard, that he was.  What the second interpretation adds is that Yisro's happiness did not come naturally at this time.  Yisro pushed himself to celebrate even though inside his heart was heavy.  It was not a joy of sasson or simcha, but merely a joy of chedvah.

This year we have a Yom ha'Atzmaut not of simcha, not of sasson, but of chedvah.  We have to celebrate even as we still grieve and mourn the events of 10/7 and for those who have fallen in battle.

That being said, rest assured that the words of the navi (Yeshayahu 51) will be ultimately be fulfilled:

כי־נחם ה׳ ציון נחם כל־חרבתיה וישׂם מדברה כעדן וערבתה כגן־יהוה שׂשׂון ושׂמחה ימצא בה תודה וקול זמרה׃