The 70-Year Time Limit

U’lema’an t’sapeir b’aznei bincha u’ben bincha es asher hisalalti b’Mitzrayim v’es ososai asher samti vam vi’yedatem ki ani Hashem (Shemos 10:2)

In his Ruach Chaim commentary on Pirkei Avos (3:1), Harav Chaim Volozhiner references a kabbalistic concept that he calls “Sod ilan charuvin alma d’charuva — the secret of the carob tree, the world that is destroyed.” What does this mean?

Harav Yisroel Reisman explains that every 70 years, which is the average lifespan of a carob tree (Taanis 23a), the world fundamentally changes. Seventy years represents a significant period of time, during which values, mentalities, and philosophies are completely transformed. This is alluded to by the Gemara’s teaching (Menachos 44a) that the chilazon, an aquatic creature whose blood is used to create the blue techeiles dye for tzitzis, ascends from the sea only once every 70 years. The Gemara (ibid., 43b) teaches that the color of techeiles is intended to remind us of the Kisei Hakavod (Hashem’s Throne of Glory), and the chilazon’s practice is intended to teach us that the perception and service of Hashem changes every 70 years.

The Gemara (Taanis 23a) records that Choni HaMe’agel slept for 70 years. Upon awaking in a new world and reality, he went to the beis medrash, where he found Torah scholars commenting that the material was as clear to them as it had been to Choni, who was capable of answering any questions and resolving any difficulties that arose.

When Choni heard this, he told them that he was, in fact, the renowned Choni HaMe’agel, but they did not believe him and did not give him the respect to which he was accustomed. This experience left Choni depressed and uninterested in continuing to live.

Rav Reisman points out that this Gemara is difficult to understand for two reasons. First, why would a great Sage like Choni become despondent simply because people did not show him honor? Second, since Choni did not forget any of his Torah knowledge, why didn’t he simply prove his identity by teaching a class to share his prodigious wisdom with the other scholars in the beis medrash?

Extending Rav Chaim Volozhiner’s teaching, Rav Reisman answers that each generation has its own unique approach and connection to the Torah, as they adopt the style that is best suited for their strengths and personality. For example, the rigorously in-depth method of meticulously studying Gemara that is prevalent in many yeshivos today is certainly a significant departure from the approach of previous generations. Therefore, when Choni returned to the beis medrash after 70 years and attempted to discuss Torah subjects with the Rabbis, he was unable to, not because he had changed, but because 70 years later, the world had changed. This left Choni depressed and dejected, as he felt out of place in the new world in which he found himself.

Applying this concept to Parashas Bo, Hashem told Moshe that one of the purposes of the plagues was to make sure that we will relate to our sons and grandsons what transpired in Egypt and all the miracles that Hashem performed there. However, in that generation, it was common to live 100 years or more and to merit having great-grandchildren and even great-great-grandchildren. If so, why did Hashem limit the transmission of this information to a person’s children and grandchildren?

Rav Reisman explains that the Torah is teaching us that although a person can relate to his sons and grandsons, he will not be able to form the same connection with subsequent generations, who will be too far removed from him in mentality and style.

Applying this insight to our generation, Rav Reisman adds that we have just passed the 70-year anniversary of the end of the Holocaust. Accordingly, our ability to connect to those important historical events and those who survived them will also change. With the passage of time, it will become increasingly difficult to relate to the unspeakable tragedies that took place. Before the flames of connection are completely extinguished, we must grab the opportunity and endeavor to learn the appropriate lessons by interacting with the remaining survivors and internalizing the events in a meaningful way before it is too late.

Q: How were the Jewish people able to fulfill the mitzvah of wearing tefillin (13:16) during their 40-year sojourn in the desert when they are invalid without all four sections of the Torah contained within, and two of the required sections weren’t even taught by Moshe until the book of Devarim, in the last year of their travels through the wilderness?

A: This question is raised in the commentary on Menachos ascribed to the Rashba, who answers that even though at this time the Torah portions they had received only contained two of the four sections that are placed in tefillin, Moshe orally taught them the other two sections so that they could be written in their tefillin throughout their 40-year sojourn in the wilderness.

Harav Gedaliah Schorr adds that the four portions that are written in tefillin are not written as copies of the sections that appear in the Torah. Rather, they are four sections that we were commanded to write in our tefillin, which happen to also be in the Torah, which explains why they could be written even before the corresponding section was given as part of the Torah.

However, the Chavatzeles HaSharon notes that the Brisker Rav argues and maintains that the four portions written in tefillin are, in fact, merely copies of parallel sections that appear in the Torah, in which case the Rashba’s answer would be difficult to understand.

The Panim Yafos, in fact, writes that the Jews did not wear tefillin in the wilderness until they received the final two portions, and this is also the opinion of the Ra’avan, although the Chavatzeles HaSharon cites two Midrashim that explicitly state that the Jews wore tefillin in the wilderness.

The Malbim suggests that the question of whether the Jews wore tefillin in the wilderness is dependent on a Talmudic dispute (Gittin 60a) between Rav Yochanan and Reish Lakish regarding whether the Torah was given to the Jews all at once at the end of Moshe’s life, or in partial segments throughout their sojourn in the wilderness.

Originally from Kansas City, Rabbi Ozer Alport graduated from Harvard, learned in Mir Yerushalayim for five years, and now lives in Brooklyn, where he learns in Yeshivas Beis Yosef, is the author of the recently-published sefer Parsha Potpourri, and gives weekly shiurim. To send comments to the author or to receive his Divrei Torah weekly, please email