The period of “counting the Omer”, connecting Pesach and Shavuot, symbolizes the upward movement from physical freedom (the Exodus from Egypt) towards spiritual liberation (the giving of the Torah). The Torah emphasizes the importance of the daily counting by means of the command to number the days in their own right, thereby expressing the importance of each and every day – not only the final aim of the process as a whole.
As we know, the mourning customs that are observed during this period cease – in many communities – on Lag Ba-Omer, and do not continue until the end of the counting, on Shavuot. This is so despite the fact that the Gemara teaches that the plague that struck down the thousands of students of Rabbi Akiva – which is the reason for our mourning during this time – continued throughout the Omer period, from Pesach until Shavuot.
The somewhat technical-sounding reason for this is that Lag Ba-Omer (literally, “the 33rd day of the Omer”) is the anniversary of R. Shimon bar Yohai’s death – an occasion that was adopted as a special, holy day in the middle of the Omer period, and which ends the mourning customs traditionally observed until that day. But the connection between Rabbi Shimon bar Yohai and the death of Rabbi Akiva’s disciples is not clear: why should it be this day that indicates the conclusion of our mourning for 24,000 Torah sages? Why not Yom ha-Atzma’ut? Or Yom Yerushalayim? Is there something special about Lag Ba-Omer beyond its marking the “yahrzeit” of Rabbi Shimon bar Yohai?
Counting the days that have passed since the bringing of the Omer sacrifice – rather than the number of days remaining until Shavuot – expresses, as we have said, the importance of each day as another step in our ascent. The number of days that we have lived and experienced, ascended and progressed, is more important, in this sense, than the number of days remaining.
What is the “ascent” that we are supposed to make on the path towards Shavuot? Apparently, it is connected to the giving of the Torah, preparing for it, preparing ourselves. The preparation for the giving of the Torah takes place, first and foremost, in the heart of every individual. Every person must work to ready his heart to accept the yoke of heaven. A person must be able to relinquish certain wants, to accept authority, to bend, to be prepared sometimes to do without understanding, etc. Lag Ba-Omer (the 33rd day of the Omer) comes after 32 days (in Hebrew numerology, “lev” – a heart) of counting, and precedes the 17 (“tov” – good) days that are left. The total number of days we count hints at the preparation that is necessary for receiving the Torah: a “good heart”. Lag Ba-Omer is located after we have completed the stage of the “heart”, hinting at the rectification and preparation of the all the good that is in him in order to reach the level of standing at Mount Sinai. This stage cannot take place in the atmosphere of mourning that has surrounded us thus far, and therefore we curtail it.
Lag Ba-Omer, then, is located at a most significant point in the Omer period; it marks the transition that takes place within a person who engages in this counting, from a state of contracting and correcting oneself to one of ascent and elevation towards the spiritual climax – the festival of the giving of the Torah!