A Tree of the Field

The fifteenth of Shevat, Rosh HaShanah for trees, teaches that to avoid spiritual death a Jew must always remain attached to his source, Torah and Judaism, and continuously grow in his service to G-d. Such service should not be performed coldly, from force of habit, but with warmth and life.

The fifteenth day of the month of Shevat is Rosh HaShanah for trees.[1] This has special significance for Jews, each of whom is compared to a tree, as written, "For man is as a tree of the field."[2] 

A tree begins from a seed. It grows, reaches maturity, yields fruit, and from its seeds other trees grow and yield fruit. So, too, the human life cycle. Man begins from an embryo, grows, matures, and yields fruit, which in the case of a Jew is Torah and mitzvos.[3] And, just as other trees eventually sprout forth from a tree's seeds, so one must ensure that other Jews grow spiritually and yield their own "fruit." A Jew cannot rest content with his own spiritual harvest but must bring other Jews near to their heritage.

A tree is part of the plant kingdom. Plants, unlike animals, die if uprooted from the earth; they exist and grow only when they continue to receive nourishment from their source. A Jew, too, lives and grows spiritually only when connected to his source, Torah and Judaism. It is not enough that a Jew once learned Torah, once performed mitzvos. He must constantly receive nourishment from his roots or risk spiritual death.

Necessity And Pleasure In Torah

Rosh HaShanah for trees is celebrated by eating fruit.[4] Specifically, it is customary to eat fruit with which the land of Eretz Yisroel is praised. There are seven kinds of produce with which Eretz Yisroel is specially blessed, mentioned in the verse, "A land of wheat and barley, and vine and fig-trees and pomegranates, a land of olive trees and honey (of dates)."[5] Of these seven, two, wheat and barley, are grain, and the other five are fruit.

From wheat and barley bread is made; and bread is basic to a person's diet, a necessity for sustaining life. Fruit is eaten for pleasure. Torah is sometimes compared to bread[6] and water[7] - necessities; and sometimes to wine,[8] oil,[9] and honey[10] - foods for pleasure. The former refers to the revealed dimension of Torah, Talmud, halachah, etc., because it must be studied by all Jews, at all times, under all circumstances. The latter corresponds to the mystical part of Torah, for its study was not always obligatory on all Jews. In earlier generations, the study of the mystical realm was limited to a select few, whose lofty spiritual stature rendered them capable of appreciating its profundity.

Supplement To Spiritual Diet

That, however, was in earlier times. In recent generations, it has become obligatory for all Jews to learn the mystical realm of Torah, as R. Schneur Zalman of Liadi, the Alter Rebbe, rules in his Shulchan Aruch.[11]

This change occurred because of the spiritual decline of the Jewish people over the generations. In former years, Jewry was robust enough to need only "bread" and "water" to keep spiritually healthy. But as its spiritual health declined, bare necessities were not enough; a supplement to Jewry's diet was needed, food to give increased strength and vigor. That food is the study of the mystical realm, the "fruit" which provides pleasure.[12]

Thus we find that from the time of the AriZal on, it became a mitzvah, a command and obligation, to reveal the secrets of the hidden dimension of Torah.[13] This received added impetus with the founding of Chassidus by the Baal Shem Tov, and reached its culmination in Chabad, which made Chassidus available to all Jews as a disciplined, intellectual approach of service to G-d.

Reason For Eating Fruit

The fifteenth of Shevat is not a festival mandated by the Written Law, as, for example, are Pesach, Shavuos and Sukkos. Nor is it found in the Oral Law, unlike Chanukah and Purim, each of which is called a festival, and on which the special prayer Al HaNissim is recited. In Mishnah,1 the fifteenth of Shevat is mentioned as the Rosh HaShanah for Trees, but there is no mention of it as a festival. Its celebration is purely a Jewish custom; likewise, the Magen Avraham rules,[14] it is a custom to eat fruit on this day.

Precisely because the fulfillment of something mentioned specifically in the Written or Oral Law is mandatory, it does not provide special pleasure for a Jew's soul. A custom, on the other hand, is not (as) obligatory on a Jew, and his soul therefore has special pleasure in carrying it out.

In slightly different words: A Jew's guide for conduct is the halachah, Jewish law, which sets out the basic, minimum standard of fulfilling Torah and mitzvos. A custom is an increase beyond that demanded by the halachah. G-d, the Giver of the Torah, receives special pleasure when a Jew conducts himself beyond its minimum requirements. And the knowledge that one has merited to provide pleasure for G-d automatically produces the greatest pleasure for a Jew.

Fruit, we have said, provides pleasure. Since the observance of the fifteenth of Shevat is a custom, it is celebrated by eating fruit specifically, for both customs and fruit are the idea of pleasure.

Performance Of Mitzvos With Pleasure

There is a lesson in this for man's service to G-d. The observance of the fifteenth of Shevat - a custom - teaches a Jew that his service should not remain limited to those matters which are absolutely mandatory. A Jew must constantly add to his service to G-d, thereby providing pleasure for both his Creator and himself. No matter how lofty his present level, he cannot remain static; he must always rise higher.

Mitzvos must not be performed routinely and coldly, from force of habit. A Jew must be involved so totally in Torah and mitzvos that his observance of them is pure pleasure. An example: The Jews, after their exodus from Egypt, ate manna, which possessed the miraculous property that one could choose that it have the taste of whichever food he so desired.[15] So too Torah and mitzvos:[16] they possess different types of pleasure, represented by the different tastes of the five fruits with which Eretz Yisroel is blessed. One need but have the necessary desire, and his fulfillment of Torah and mitzvos can be pleasurable, not just routine.

This is achieved through the study of Chassidus, which, we have previously noted, is the concept of "pleasure." The revealed aspect of Torah is the body of the Torah; the mystical aspect, Chassidus, is its soul. The study of Chassidus brings warmth and vitality to one's performance of mitzvos, infusing new life, ensuing that one's Torah and mitzvos will no longer be sterile; they will have a soul.

Full And Complete Service

A further aspect of this festival is that it is on the fifteenth of Shevat, when the moon is at its fullest.[17] The Jewish people are compared to the moon,[18] and "they are destined to be renewed like it."[19] Thus the different phases of the moon parallel and are reflected in Jews' service to G-d. The full moon on the fifteenth of the month represents complete and full service to G-d.

No matter how lofty a Jew's previous achievements (on the preceding days of the month), the fifteenth teaches he can and must do more: he must grow as the moon grows, until his achievements are full and complete. This is carried out, as explained above, by having pleasure in our service to G-d. When that service has been fully completed, the true and complete redemption will have come.

Sichos 15 Shevat, 5742; Likkutei Sichos, Vol. XVI, pp. 529-532

Notes: 
1. Rosh HaShanah 2a. 
2. Devarim 20:19. That "man" refers specifically to Jews we learn from the verse "You are called man" (Yevamos 61a). 
3. Sotah 46a; see Likkutei Torah, Parshas Emor, p. 70. 
4. Magen Avraham, Shulchan Aruch, Orach Chayim 131:6, no. 16. 
5. Devarim 8:8. 
6. Shabbos 120a; Chagigah 14a. 
7. Bava Kamma 17a. 
8. Berachos 57a; Avodah Zarah 35a. 
9. Shir HaShirim Rabbah 1:3. 
10. Ibid., 1:2. 
11. Shulchan Aruch Admur HaZakein, Hilchos Talmud Torah 1:4. 
12. See above The Beauty Of Pearls, p. 65ff., for a further discussion on why the study of Chassidus is necessary in the latter generations specifically. 
13. Tanya, p. 284. 
14. Magen Avraham, loc. cit. 
15. Yoma 75a. 
16. Manna is called "bread from heaven", indicating that even in the revealed dimension of Torah ("necessity"), one can and must derive pleasure. 
17. Shemos Rabbah 15:26; Zohar, Vol. I, p. 150a. 
18. Sukkah 29a; Bereishis Rabbah 6:3. 
19. Sanhedrin 42a.