Sometimes I wonder at the puny specimens passing themselves off as Bar Mitzvah boys. It's okay for the occasional mature young man: voice already broken, peach fuzz on the cheeks, and tall enough to reach the podium without standing on a box; but I spare some sympathy for those not so physically well-endowed. They of the reedy sopranos and short stature and too tiny to shop in an adult clothing store. How, by any stretch of the imagination, can they be described as having reached adulthood?

It is not their fault they develop behind schedule. When G‑d established a fixed age for ascension to adulthood, it was inevitable that some of the troops would rank at the rear of the bell curve. One's physical maturity at thirteen is no indicator of genetic potential, as demonstrated by the fact that I was recently passed in height by one of the smallest Bar Mitzvah boys I ever taught.

The giant Og mocked Abraham for assigning all his hopes to "a scrawny runt..."We read this week of the first Bar Mitzvah ceremony ever conducted. When our forefather Isaac came of age, his father Abraham threw a party to celebrate (Genesis 21:8). Some of the guests, the Midrash relates, could not contain their derision. The giant Og is recorded to have mocked Abraham for assigning all his hopes and aspirations to "a scrawny runt of a child who could be crushed under my finger."

History has had the last laugh on Og and anti-Semites of his ilk. Where are all those warriors and strongmen who boasted of their courage and swaggered their way through life? Consigned to the dustbin of history, their bubble of hot air punctured and their names forgotten, while Isaac's descendants still play their part on the world stage.

A Jew has greater aspirations than strength and physique. The Bar Mitzvah ceremony celebrates one's emotional and physical maturity, not height or athletic ability. Coming of age as a Jew entails committing to a lifelong training program, bulking up on moral clarity and striving to reach a peak of religious fitness.

Our Torah and its precepts are the secret of our fantastic longevity, and this was what Abraham was celebrating — his son's ascension to true adulthood and full mitzvah observance.