Shimon and Levi as Source for Bar Mitzvah

Shimon & Levi were adults at time of their action in Shechem (a source of 13 for Bar Mitzvah) see table below. At this age one reaches the adult maturity to serve with logic & comprehension; but also, “each man took his sword” shows that one must also approach Mitzvos with mesiras nefesh which transcends logic. Divine service must begin with acceptance of the Divine Yoke, ensuring that one is not blinded by their own logic; afterwards one applies their intellect and comprehension to the service of HaShem.