Perhaps one of the lesser known Mitzvot (definitely the least commercialized), is the mitzvah of “Sefirat Ha’omer” (“the Counting of the Omer”). (The source for this mitzvah is in Vayikra (Leviticus) 23:15-16). From the second day of Passover until the holiday of Shavuot there are exactly 7 weeks. (Shavuot commemorates the giving of the Torah and the revelation at
According to the teachings of Kabbalah and the deeper dimensions of the Torah, this period is also one of self-refinement. There are seven traits which define us. Each of them comprise of seven (totaling 49). During this period we spend the time refining each of these 49 traits; bettering ourselves in preparation for receiving the Torah. (More about “Counting the Omer” here including a day-by-day spiritual guide).
An interesting point about this mitzvah is that on one hand each day is considered a separate mitzvah, as evident in the requirement to pronounce a separate blessing each night as we count. On the other hand, it is a continuation of the previous night; we begin with one, the next night two etc. Straddling these two sides is the law that if one forgot to count one night they should continue to count, however without saying the blessing.
This creates some curious problems in Jewish law. If a child begins the 49 day period under Bar/Bat Mitzvah, (at which time their requirement to fulfill mitzvot is Rabbinical), and during the 49 days they become Bar/Bat Mitzvah, (at which time their requirement now becomes Biblical). Do they continue counting with a blessing? In other words, was their counting until now considered a valid counting (even though they were only required by the Rabbi’s (not Biblically)) and therefore they may continue to count with a blessing, or do we consider their previous “counting” to be invalid and therefore they can only continue to count without the blessing?