Who Knows 13?

Rabbi Akiva says: I might have thought that a person should don phylacteries on Shabbatot and Festivals. Therefore, the verse states: “And it shall be for a sign for you on your arm, and for a remembrance between your eyes, so that God’s law shall be in your mouth; for with a strong arm God brought you out of Egypt” (Exodus 13:9). The obligation to don phylacteries applies when Jews require a sign to assert their Judaism and their status as the Chosen People, i.e., during the week, excluding Shabbat and Festivals, as they are themselves signs of Israel’s status as the Chosen People and a remembrance of the exodus from Egypt. Consequently, no further sign is required on these days. This teaching proves that Rabbi Akiva maintains that Shabbat is not a fit time for donning phylacteries.

(1) ...It is prohibited to wear tefillin on Shabbos or Yom Tov since they are an אות (a sign) and if one were to also wear an extra sign it would be a disgrace to their sign.

(2) ...On Chol HaMoed it is prohibited to wear tefillin for the same reason, namely that Chol HaMoed is also an אות (sign). Rema: There are those who maintain that one is obligated to wear tefillin on Chol HaMoed [Beit Yosef quoting the Rosh] and the custom in all these regions is to put on tefillin with a beracha. The only difference is that the beracha is not recited out loud in shul as is normally done.

An adult, is one whose thirteenth year has passed and he has entered his fourteenth year...

AT THIRTEEN, THE COMMANDMENTS. Rav: for the verse says, “should a man or woman commit one of the sins of man” (Numbers 5:6), and in the story of Shechem the verse says “and the two sons of Jacob, Simon and Levi, the brothers of Dina, each [Heb. ish] took their swords” (Genesis 34:25), and Levi was thirteen at the time, and is called ish, a man. Rashi: consider that Jacob spent another thirteen yars with Laban after marrying Leah. If one allows seven months for each of her pregnancies, then since Levi was the third pregnancy, he was born about two years in. He would then have been eleven years old when they left. Add to that the six months they spent on the road and the eighteen months—a summer, a winter, and another summer—that they spent in Sukkot, which makes two years altogether, and it turns out that Levi was thirteen years old when they arrived at Shechem, and was called ish, a man. In his commentary on the Torah, in parashat Vayeshev, on the verse “and he mourned his son many days” (Genesis 37:34), Rashi is not being precise when he writes that six months of that two-year period were spent in Beit El, as that happened after the incident in Shechem. [*See Zavim, 2:1.]

(10) ..."...And the youths grew up" (Bereishit 25:27)... So too with these, for thirteen years they both went to school (beit hasefer) and came back from school, but after thirteen years this one went to study-houses (batei midrashot) and this one went to idolatrous temples (batei avodat kochavim). Rabbi Elazar said, until thirteen years a person needs to take care of their children - from this age onwards, they need to say "Blessed is the one who has exempted me from the punishment of this one."​​​​​​​

(2) You must know, that a man is acted upon according to his actions...

It is a natural tendency of man to be influenced in his ideas and conduct by his fellows and associates, and to follow the usage of the people of his state...