It was 29 years ago on this date - 7 Iyar (which was on Yom Revi'i like it is this year) - that Rabbi Moshe Feinstein ZT"L, the leading Posek of the previous generation, wrote a Haskomo (approbation) for the Petek following his meeting with Saba. Not that the Petek, which is signed by Rabbeinu himself, needed a Haskomo, as Saba noted, but the purpose of this was in order to prevent challenges to Saba's outreach efforts to bring Jews close to Yiddishkeit and Breslov Chasidus in the last 10 years of his life.
It is true that the date on the Haskomo for the Petek is written as the usual Hebrew date, without mention of the day of the Sephira which is the 22nd day of the Omer; nevertheless, one can see the close connection between the Petek and the Kabbalistic Sephira of the day - Chesed She'B'Netzach - Kindness within Eternity/Victory.
First to note, Rabbeinu's name shares the same Gematria as the Sephira word Netzach - 148. And just as Rabbeinu was Niftar on the fourth/middle day of the seven days of Succos, so is Netzach the fourth/middle of the seven Sephiros which correspond to the 7*7 days of the Sephira period. Moreover, Rabbeinu was Niftar on the day that is represented by Moshe Rabbeinu of the seven Ushpizin, who in turn was born and Niftar on 7 Adar, the same date that Rabbi Moshe Feinstein, who was named after Moshe Rabbeinu, was born on. In fact, there is a Remez to Rabbeinu in a Posuk in Parshas Ki Sisa (Exodus 32:32) which identifies him as Ani Nachman MeUman, and the word Na (please) - which is part of the word Ani (I) - is also the Hebrew number 51 (Noon-Aleph), which is the exact amount of words in the Petek.
As we see in the SEVENTH line of the Petek - Na Nach Nachma Nachman MeUman - it follows the same pattern of Poshut, Koful, Meshulosh, Rabua as the main name of Hashem YKVK (K being substituted here for the letter H) when spelled as Y YK YKV YKVK, which shares the same Gematria as the Sephira word Chesed - 72 (as mentioned in Tikunei Zohar).
As you can see, based on the above, there is a close connection between the Sephiros of Chesed and Netzach as they relate to both Hashem's and Rabbeinu's names. Now, as we note the particular Kabbalistic Sephira of the day as Chesed She'B'Netzach, the word She'B'Netzach shares the same Gematria as the word Shefa (flow) - 450. Indeed, in the final paragraph of the customary Sephira prayers found in virtually every Siddur, we say the following immediately after noting the particular Kabbalistic Sephira of the day - V'Al Yeday Zeh Yushpa SHEFA Rav B'Chol HaOlamos - "through this, there will be much (spiritual) flow spread through all the worlds..."
And as we say particularly - Shefa RAV "much flow", the word Rav (much) also spells the Hebrew number 202 (Reish-Beis/Veis), and this past 4th day of Succos (18 Tishrei) was the 202th Yahrzeit of Rabbeinu. This brings in to mind about what it states about Tzadikim that they can effect more spirituality for this world after their passing than even before their passing, because they are no longer restricted in a physical body.
Now, some may have a general question. Why with all of these Kabbalistic Sephiros, do we say particularly for example Chesed She'B'Netzach (Kindness THAT IS in Eternity/Victory) - instead of Chesed B'Netzach - using the letter Shin, which seems superfluous. While I don't have the answer to this question, if you do take a close look at the word She'B'Netzach, we can see that the letters of this word spells the following Roshei Taivos (backwards) - Chasidus (of the) Tzadik - Nachman Ben Simcha (Cheis-Tzadi-Noon-Beis-Shin). And after at least the little that we have learned and retained in our minds of Breslov Chasidus, what is a better way of rectifying the blemishes that were, Chas V'Shalom, made of these Sephiros? No doubt, it is the flow of the teachings of Rabbeinu that we seek to penetrate all the worlds, especially in order that "we will be purified and sanctified in Your High Holiness". It is this particular form of CHASIDUS that is the greatest CHESED - whose Roshei Teivos (backwords) spells Daf Sefer Chasidus ("One page of Rabbeinu's Seforim will be the Tikkun for everything") - of the Ribono Shel Olam to help us achieve VICTORY over our Yetzer Hara which will result in our ETERNITY.
And as connected with Rabbeinu's main Talmid - Rabbi Nosson Sternhartz (HaMoharanit) - the Gematria of Chesed She'B'Netzach is 522 - which is a composite of 500 - the Gematria of Rabbi Nosson's name, and 22 - representing this 22nd day of the Sephira. V'NOSSAN Lonu Es Toraso "Hashem GAVE us His Torah", the Torah that is composed of the 22 letters of the Aleph Beis. Boruch Ata Hashem NOSEIN HaTorah - "Blessed is Hashem the Giver of THE TORAH", as the word HaTorah shares the same Gematria as the name of Rabbi Nosson's main work Likutei Halochos - 616, which is Chasidus on the entire FOUR sections of the Shulchan Aruch, of which a Chasidishe Rebbe noted that this work includes ALL the other works of Chasidus! For after all, in essence, all of Rabbi Nosson's teachings are in fact Rabbeinu's teachings (as noted in the Sefer Cochvei Ohr).
And it is the Petek, which came to Saba as a reassurance of his Avodas Hashem from Rabbeinu, which is an aspect of Rabbeinu's Chesed encouraging Saba in terms of Netzach - using his spiritual energies to overcome his materialism, despite the setback of Saba eating on the morning of 17 Tammuz.
Finally, as we learn from Avrohom Ovinu, who represents the Sephira of Chesed, the kindness that we do for others - whether small or big - especially in the way of a spiritual favor in teaching Torah or Hafatza/Kiruv, which is the ultimate kindness that we can do for another, will have ETERNAL value, an everlasting impact on the individual/others for all eternity. At times, this involves Mesirus Nefesh, just as Moshe Rabbeinu, who represents the Sephira of Netzach, employed in saving the Jewish people following the sin of the Eigel HaZohov on 17 Tammuz, putting his own self being on the line - taking a chance to having himself erased from the entire Torah, devoiding himself of all spiritual merits, in his great Ahavas Yisroel for the Jewish people.