Bar/Bat Mitzvah in Jewish Sources

(10) Rabbi Levi offered a parable: They [Jacob and Esau] were like a myrtle and a wild rosebush growing side by side; when they matured and blossomed, one yielded its fragrance and the other its thorns. For thirteen years both went to school and came home from school, [but] after this age, one went to the house of study and the other to idolatrous shrines. Rabbi Eleazar said: A parent is responsible for his/her child until the age of thirteen, at which point the parent must say: Baruch sheptarani mei’ansho shel zeh, “Blessed is the One who has now freed me from the responsibility of this child.”

(21) He [Yehudah ben Teima] used to say: Five years [is the age] for [the study of] Scripture, Ten [is the age] for [the study of] Mishnah, Thirteen [is the age] for [observing] commandments, Fifteen [is the age] for [the study of] Talmud, Eighteen [is the age] for the [wedding] canopy, Twenty [is the age] for pursuit, Thirty [is the age] for [full] strength, Forty [is the age] for understanding, Fifty [is the age] for [giving] counsel, Sixty [is the age] for mature age, Seventy [is the age] for a hoary head, Eighty [is the age] for [superadded] strength, Ninety [is the age] for [a] bending [stature], One hundred, is [the age at which one is] as if dead, passed away, and ceased from the world.

(6) Regarding a girl of eleven years and one day, her vows are examined [i.e she is questioned in order to determine if her vows are valid]. At twelve years and one day, her vows stand. And we examine [her vows] for the entire twelfth [year]. Regarding a boy of twelve years and one day, his vows are examined [to determine if they are valid]. At thirteen years and one day, his vows stand. And we examine [his vows] for the entire thirteenth [year]. Prior to this time [i.e. eleven years and one day for a girl and twelve years and one day for a boy], even if they said, "We know in whose name we vowed, and in whose name we sanctified," their vows are not vows and their sanctifications are not sanctified property. After this time, even if they say, "We do not know in whose name we vowed, and in whose name we sanctified," their vows are vows and their sanctifications are santified property.

Bar mitzvah - that is, when he turns 13 and 1 day. It has become the custom not to say the blessing (of barukh shepetarani) until the lad prays with the congregation as its leader or reads from the Torah for the first time on Shabbat, thus making it known that he is bar mitzvah.

It is a mitzvah to make a festive meal on the day when one's son becomes bar mitzvah, just like the day when he enters the chupah....And the reason for the festive meal is that now he has become a man in Israel, commanded in the Torah's commandments....