From Chapter Six of Rabbi Shloma Majeski ’s Likkutei Mekoros (Underlined text is the compiler’s emphasis(
Translated by Boruch Merkur
8. As discussed above, Shabbos Nachamu emphasizes the infinite quality (keifel, doubled) of the true and complete redemption. There is, however, further emphasis this year, when Shabbos Nachamu follows the great preparatory day of Erev Shabbos (“one who is busy during Erev Shabbos shall eat on Shabbos”) on the fifteenth of Av.
But first to preface with an explanation of the connection between the fifteenth of Av (especially when it falls on Friday) to the true and complete redemption:
The fifteenth day of the month, when “the moon is full,” alludes to the fullness, the perfection, of the Jewish people. [Contrary to the Gentile nations who use a solar calendar] the Jewish people follow the lunar calendar. Indeed, the Talmud asserts that the Jewish people “resemble the moon” (see Sukka 29a), and “are destined to be renewed like it” (liturgy of Kiddush Levana) in the true and complete redemption by Dovid Malka Meshicha (who is associated with the moon, S’firas HaMalchus).
The fifteenth of the month of Menachem-Av (the name “Menachem” preceding “Av”) expresses the fullness of the month that is called by the name of Moshiach – “Menachem is his name.” Also, the birth of Moshiach (when “his mazel rules”) is in this month (on Tisha B’Av, and when the moon is full, on the fifteenth of the month of Menachem-Av, it is known with certainty that Moshiach has already been born*), the month whose mazel is Aryeh, the month when “Aryeh will come…and rebuild Ariel.”
NOTES:
*Footnote 83: As we find regarding the k’vius of the Yom Tov of the Fifteenth of Av on the day when the men stopped dying in the desert, although the nullification of the decree already took place on Tisha B’Av (Taanis 30b, end; commentary of Rashi and Tosafos from Eicha Rabba P’sichta 33).
(From the address of Shabbos Parshas VaEs’chanan, Shabbos Nachamu, 16 Menachem-Av; Seifer HaSichos 5751, pg. 743)