In the Torah portion of Vayishlach we read about Dinah’s brothers, Shimon and Levi: “each man took his sword,”1 in order to avenge their sister’s violation by Shechem. Shimon and Levi were at that time 13 years old.2

According to some opinions,3 since at the age of 13 Shimon and Levi were deemed “men” — a term that denotes maturity, as the verse states:4 “Strengthen yourself and become a man” — we derive the law that “at the age of 13 one becomes obligated to perform the mitzvos.”5

In other words, by the age of 13 one has acquired the intellectual characteristics and attitudes of an adult — maturity of intellect and discernment. It is for this reason that a person is then obligated to perform all the commandments.

Although it is possible to be intellectually acute even before the age of 13, maturity is still lacking, both with regard to the dearness and merit of performing mitzvos , as well as with regard to the severity of the sin in their non-performance.6 Accordingly, a pre-teen is not held responsible for his conduct and actions, and the obligation of mitzvos cannot be placed upon him.

According to another opinion, however, the source for the obligation to perform mitzvos at age 13 is a dictate handed down by G‑d to Moshe at Sinai.7 As such, it follows along the lines of other supra-rational edicts regarding measurements and amounts. According to this opinion, the obligation to perform mitzvos at 13 has nothing to do with maturity or discernment; it is a supra-rational law.

One of the Halachic differences between these two opinions is the age at which a non-Jew becomes obligated to observe the Seven Noahide Laws.

If the obligation of mitzvos at the age of 13 is dependent on the age at which (most) people reach maturity, then it should apply to Jew and non-Jew equally. If, however, it is one of the supra-rational Laws of Measures — which do not apply to non-Jews8 — then the age at which non-Jews’ are obligated to perform their seven commandments depends entirely on individual maturity.9

In terms of spiritual service, the difference between these two opinions relates to the manner in which a Jew is to approach the performance of Torah and mitzvos :

According to the first opinion, the approach is one of serving G‑d logically; if the age at which one becomes obligated to perform mitzvos depends on one’ intellectual maturity, it is understandable that the service commences with logic and comprehension.

According to the second opinion, however, the obligation to begin performing mitzvos at 13 is supra-rational — because G‑d has so commanded. It therefore follows that the approach to the performance of mitzvos involves the supra-rational acceptance of the Divine Yoke.

Nevertheless, even those who hold the first opinion — that the age for beginning one’s service is gleaned from the verse “each man took his sword” — also agree that the performance of mitzvos is bound up with mesirus nefesh, i.e., serving G‑d in a self-sacrificial manner that transcends the bounds of intellect.

That this is indeed so is amply demonstrated10 by the fact that those who hold this opinion derive it from the verse “each man took his sword ” — an action that demands self-sacrifice.

This in no way contradicts the earlier statement that this manner of service demands comprehension and intellect, for though they maintain that the action should be performed with understanding and discernment, they agree that the foundation of Divine service lies in acceptance of the Divine Yoke. Then, and only then, can a person be assured that he will not be blinded by his own logic, and that his performance of mitzvos will be done in an entirely proper manner.

Based on Likkutei Sichos Vol. XV, pp. 289-292.