Av and Elul, the eleventh and twelfth months of the Jewish year, are end to end in the calendar but worlds apart in character and temperament. In Av we grapple with the darkest moments of Jewish history. Elul is also a somber month, but hers is a solemnity buoyed by joyous yearning. Elul is the month of divine mercy—the month in which the Almighty draws nearer to the soul of man and the soul of man is stimulated to teshuvah, return to her pristine essence and rapprochement with her G-d.
The diverse characters of Av and Elul were forged in the genesis of Jewish history. In the first year following the Exodus, Moses ascended three times to the summit of Mount Sinai, each time for forty days. The first ascent (Sivan 7 to Tammuz 17), was to receive the Torah from G-d. Following Israel’s worship of the Golden Calf, Moses spent a second period of forty days (Tammuz 18 to Av 29), pleading with G-d to forgive His people. This second period is characterized by our sages as a time of divine anger and judgment. Finally, Moses spent a third period of forty days (Elul 1 to Tishrei 10) atop the mountain, during which time he secured G-d’s full forgiveness for Israel and received from G-d the “second tablets” to replace those which had been broken as a result of Israel’s sin. These were forty days of mercy and goodwill, culminating in Yom Kippur which was then established by G-d as a day of teshuvah for all time. Thus, the month of Av, which belongs to the second forty-day period, is a month of din—harshness and judgment—while Elul, which belongs to the third forty-day period, is the month of divine mercy (rachamim). 
Gifts of Wood
The different modes of relationship embodied by Av and Elul are expressed not only in the events and observances of these months, but also in the lives of those who came to be identified with them. An example of this concerns two families who played a role in the re-establishment of Jewish life in the Holy Land in the fourth century BCE.
When the Jewish people returned to the Land of Israel, after seventy years of exile in Babylonia, to resettle the land and rebuild the Beit Hamikdash(Holy Temple), they faced many obstacles and hardships. The community was small and poor (most Jews chose to remain in exile) and threatened by many enemies. In contrast to the gold-gilded glory of the First Temple (built by King Solomon at the peak of Jewish power and prosperity), the Temple they built was made of simple stone and mortar. The Temple treasury could not even afford to pay for firewood for the altar.
Several families came forth to resolve this crisis. Each donated a large quantity of firewood; when the supply brought by one family was exhausted, another family brought its donation. In this way, eight families supplied wood for the first critical year of the Beit Hamikdash’s existence.
To reward their generosity, the prophets of the time instituted that the date of each family’s donation should be fixed in the Temple calendar. Each year, when a particular family’s day came along, the family was granted the privilege to again supply wood for the altar, even if the Temple coffers were full and its woodroom stocked with firewood. These donations were accompanied by a special ceremony and the day celebrated as a festival by the donating family.
Two of the “Wood-Offering Days” are of special significance: the 20th of Av, on which a family called “Pachat-Moab,” from the tribe of Judah, brought wood to the Beit Hamikdash; and the 20th of Elul, which was the day of the “Adin” family, also from the tribe of Judah. The deadline for wood-cutting in the land of Israel is the fifteenth of Av, which marks the height of summer; after this date, the heat of day diminishes and the wood that is cut is more moist and prone to worming (it was forbidden to use worm-infested wood for the altar). These two families brought wood to the Temple at a time when their own wood supply could no longer be replenished with wood of good quality; hence their gifts were held in special regard. This is why the Talmud singles out these two families and engages in a lengthy discussion regarding their genealogy.
Who were “Pachat-Moab” and “Adin”? Our sages conclude that the Pachat-Moab family were descendants of Yoab ben Tzeruyah, the general of King David’s armies, while the Adin family traced its lineage to King David himself.
Thus we can understand the connection between these two families and the dates they occupy in the Jewish calendar.
The paths that human life follows are many and varied. There are scholars and businessmen, musicians and farmers, teachers and laborers. On the most basic level, all vocations and callings fall into two general categories: those that are spiritual in nature and those that deal with the material world.
The existence of the man of spirit is a tranquil one. He deals with reality on the conceptual level, where battles are waged with ideas, pathways blazed with a prayer and mountains climbed with a song. He changes the face of society with his thoughts and yearnings; he rarefies the substance of material earth by stimulating the spiritual workings of the heavens. He has no obstacles, only aspirations; no enemies, only goals.
In contrast, the practitioner of material life must struggle against a resisting environment. He must fight the falsehood, greed and outright evil in his world; he must battle the corporeality in his own nature and the obstinacy of a physical reality that obscures its spiritual essence and divine purpose.
These two prototypes of human life were personified by King David, whose life was devoted to studying Torah and composing psalms of praise to G-d, and Yoab ben Tzeruyah, who led Israel’s armies in battle against their enemies. Thus, Yoab’s descendants affirmed their relationship with the Beit Hamikdash—the vector of man’s service of G-d—on the twentieth day of the harsh, trial-rife month of Av, while the descendants of David did so on the twentieth day of the merciful month of Elul.
The soldier in the battlefield of material life and the navigator of the tranquil realm of the spirit are equally crucial to the fulfillment of the divine purpose in creation. They are also interdependent: the soldier requires the guidance of the scholar, and the spiritualist’s work is ultimately realized only in the lives of those who take up the challenge of implementing it on the physical level. As the Talmud states: “Were it not for David, Yoab could not wage war. And were it not for Yoab, David could not devote himself to Torah.”
Adapted from the teachings of the Rebbe by Yanki Tauber
. Including the tragedy of the Spies (Numbers 13-14), the destruction of both the First and Second Temples and the respective expulsions of Israel from their land, and the defeat of the Bar Kochba revolt. More recently, the month of Av has been the scene of the expulsion from Spain in 1492 and the onset of the Holocaust in 1939.
. See Rashi on Deuteronomy 9:18.
. Talmud, Taanit 12a (see Rashi), 26a and 28a.
. Ibid., 31a; Middot 2:5.
. Talmud, Taanit 28a and commentaries (see notes on pp. 87 and 88 of Likkutei Sichot, vol. IX).
. The Talmud cites several opinions on the matter, but the above conclusion is the one that best coincides with biblical and midrashic accounts (see Nehemiah 7:11 and Rashi on II Samuel 23:8).
. See The Father of the Bride, WIR, vol. VII, no. 43.
. In recent centuries, many artists, historical novelists and filmmakers have created an image of David as a warrior king. But the accounts of his life and deeds given by the Torah, Midrash, Talmud and their commentaries yields an entirely different picture. King David was the leading Torah scholar of his generation and a link in the “chain of tradition” that transmitted the entire body of Torah law from Moses onward; he headed the sanhedrin and thus was the highest judicial authority in Israel; he was the “sweet singer of Israel,” the composer of the book of Psalms who rose nightly at the stroke of midnight to sing G-d’s praises until dawn. Though he participated in several wars against Israel’s enemies (indeed, one of the reasons that David could not build the Beit Hamikdash was because, as G-d said to David, “You are a man of war and have spilled blood”—I Chronicles 28:3), in most cases, it was Yoab who led the troops in battle while David remained with his scrolls and harp.
. Talmud, Sanhedrin 49b.
. The 20th of Av is the yahrzeit of the Rebbe’s father, the gaon and kabbalist Rabbi Levi Yitzchak Schneerson (1878-1944).
. Likkutei Sichot, vol. IV, pp. 1103-1107; ibid., vol. IX, pp. 86-90.