The Mishnah in Pirkei Avot (Chapter 3, Mishnah 12) states: “When one’s deeds are greater than one’s wisdom, one’s wisdom shall last; when one’s wisdom is greater than one’s deeds, one’s wisdom shall not last.”
The Tashbetz explains in his Sefer Magen Avot regarding this teaching that this cannot be understood according to its simple meaning, for if one does not possess great wisdom, how is it possible that one can possess many good deeds? One’s good deeds are only the fruits of one’s wisdom as another Mishnah in Pirkei Avot states, “An ignoramus cannot fear sin.” Similarly, the Torah states, “And you shall learn them (the words of the Torah) and you shall keep them to perform them,” which means that through one’s learning, one’s Mitzvah performance comes about.
Rather, the explanation of this Mishnah is that when one accepts upon himself to fulfill everything that one learns, immediately upon accepting this upon himself, one is considered to have already performed these Mitzvot. He proceeds to support his explanation from various words of our Sages.
Regarding the second teaching of this Mishnah, “When one’s wisdom is greater than one’s deeds, one’s wisdom shall not last,” this can be understood simply that if one learns a great deal but does not fulfill the Mitzvot which one has learned about, one would have been better off not learning at all. The Avot of Rabbi Natan (a compilation of teachings similar to that of Pirkei Avot compiled by the great Tanna, Rabbi Natan) compares this to one who goes to a grocer and tells him, “Please give me some wine and oil.” The grocer replies, “So give me a vessel to fill it with.” The customer then hands the grocer a perforated vessel. The grocer glances at him questioningly and asks, “If you do not have vessels capable of containing wine and oil, why do you ask for them?” Similarly, Hashem tells the wicked, “If you do not possess good deeds, how do you propose to learn Torah?” The verse in Tehillim states likewise, “And to the wicked one Hashem proclaims, ‘Why do you recount my statutes?’”
Regarding what we’ve learned that “one’s wisdom shall not last,” this can be explained based on the Gemara in Masechet Sanhedrin (106b) that Do’eg the Adomite did not die before he had forgotten all of his Torah as the verse states, “He shall die without rebuke and with his great foolishness he shall err.” This was because he studies much Torah but he did not fulfill what he learned.
Halacha Yomit: It is customary not to take haircuts during the Omer period until the 33rd day of the Omer according to the Ashkenazi custom (although there are varying customs in this regard among Ashkenazi Jews) and until the 34th day of the Omer according to the Sephardic custom. Women do not observe this custom at all and they may take haircuts.