1. The Bris of the Alter Rebbe
The 25th day of Elul marks a significant event in Chabad history: it is the day the Alter Rebbe, Rabbi Schneur Zalman, was brought into the covenant of Avraham Avinu. This bris took place eight days after his birth on Chai Elul (the 18th of Elul), in the year 5505 (1745). Thus the 25th of Elul is celebrated as the day of his entry into this sacred covenant.
2. The Creation of the World and Its Connection to 25 Elul
Beyond its place in Chabad history, the 25th of Elul also holds a central place in the Jewish calendar. According to tradition, it is the day on which creation began. Since Adam was created on the sixth day, which is Rosh Hashanah, counting back five days brings us to the 25th of Elul as the first day of creation. While Rosh Hashanah commemorates the creation of man—the purpose and culmination of creation—the process itself began on this earlier date.
3. The Baal Shem Tov's Role in the Alter Rebbe's Birth
The Baal Shem Tov played an instrumental role in both the birth and the early milestones of the Alter Rebbe. His parents, Reb Baruch and Rebbetzin Rivkah, had not been blessed with children in their first months of marriage. They sought the Baal Shem Tov's blessing on his own birthday, Chai Elul, and he promised them that within a year they would have a son—a promise fulfilled with the birth of Schneur Zalman.
4. Early Milestones: The Upsherenish
The connection between the Baal Shem Tov and the Alter Rebbe continued beyond his birth. When it came time for his upsherenish—first haircut—his parents again brought him to the Baal Shem Tov, who personally performed it.
5. The Bris Meal and Torah Teachings
At the bris meal, Torah thoughts were shared by those present, expounding on the verse "on the eighth day he shall be circumcised" and its spiritual significance.
6. The Baal Shem Tov's Joy on Shabbos Nitzavim
On Shabbos Parshas Nitzavim, after the bris, the Baal Shem Tov delivered a talk on the verse "I will greatly rejoice in Hashem." He was visibly filled with great joy at that farbrengen, though many did not understand its source at the time. In truth, this joy came from the bris of Schneur Zalman and all that he would come to mean for Chassidus and for Klal Yisrael.
Notes
The Alter Rebbe's birth – see 18 Elul – the birthday of the Baal Shem Tov and the Alter Rebbe.
His parents – see 17 Elul – the wedding of Reb Baruch and Rebbetzin Rivkah and 8 Tishrei – Reb Baruch's yahrtzeit.
The Baal Shem Tov – see 6 Sivan – his yahrzeit.
The verses – "On the eighth day he shall be circumcised" is Vayikra 12:3; "I will greatly rejoice in Hashem" is Yeshayahu 61:10, from the haftorah of Parshas Nitzavim.