When a boy turns 13 years and one day he becomes obligated in all commandments of the Torah. The law is ancient and has its sources in the Written Torah, but it is principally based on the Oral Tradition and is recorded in the Babylonian Talmud in Tractate Nidah pages 47 and 48 and in Tractate Yevamot 80. It is legislated in Maimonides' Mishneh Torah, Ishut 2:1-2 and in the Code of Jewish law in Orach Chaim 55 and in Even Haezer 195. The most ancient way of marking this transition is make a festive meal (seudat mitzvah) based on the Talmud in Tracate Kidushin 31a. It is customary that the Bar Mitzvah boy prepares a speech based on the Torah portion for his Bar Mitzvah or related to the concept of their new obligation to keep the commandments.
