Rav Chaim zatzal on “What Kabalah Should a Bar Mitzvah Bochur Take Upon Himself?”
Often, a Bar Mitzvah bochur would inquire of Maran zatzal what kaballah he should take upon himself in light of his impending Bar Mitzvah. Rav Chaim would answer, “Take upon yourself the Mitzvah of Kivud Av v’Aim.”
No one around him seemed to know why it was this particular Mitzvah that Rav Chaim zatzal would recommend.
There was one time, however, where he revealed why he encouraged that this one should be the Kaballah that a Bar Mitzvah bochur should take upon himself.
It is in the Yerushalmi at the end of the first perek of Kiddushin. The Yerushalmi states there, “If he performed one Mitzvah – they grant him goodness [from Shamayim], they grant him long life, and he inherits the land.”
Maran zatzal asked, “What does it mean, ‘If he performed one Mitzvah’?”
Maran further explained, “There is an inyan to accept upon oneself one Mitzvah that he will never ever violate no matter what the circumstances. He explained that it is on this that the Yerushalmi states “they grant him goodness and extend his life.” The Yerushalmi further elaborates, “for example, Kivud Av v’aim – honoring one’s father and mother. From here we see how great this Mitzvah is and it is therefore proper for someone just entering the responsibilities of Mitzvos to observe this one to the best of his abilities.” (Lachazon b’Noam Hashem p. 105).
[RYH: This can also be seen in the Gemorah in Shabbos 118b, where Amoraim, it seems took on the idea of adopting one Mitzvah in a superb fashion. Also, in one of Rav Zilberstein’s early vavei ha’Amudim (#13), he cites this very practice from the Steipler zt”l]