"It was said that Rebbi Akiva had 12,000 pairs of students who lived between the cities of Geves and Antifras, and all of them died during one period because they didn't show proper respect one to the other. [At that point] the world was desolate of Torah, until Rebbi Akiva came to our teachers in the South, and taught it to them...and they were the ones who preserved the Torah at that time. We were taught; they all died between Pesach and Shavuot."

(Yevamot 62b)

It is customary not to take haircuts [after Pesach] until Lag Ba'omer, because it was then (on Lag Ba'omer) that [Rebbi Akiva's students] stopped dying."

(Shulchan Aruch Orach Chayim 493:2)

Perhaps we can offer some insight into these points, after first examining some of the more esoteric relationships between Pesach and Shavuot.

What are the traits necessary for growth in Torah? Although there are many specific traits that can bring a person to grow in Torah (see Avot 6:5), it is quite clear from the words of Chazal that one of the more basic ones is humility. Once one has acquired humility, the other desired traits will inevitably follow. This theme recurs many times in the words of our Rabbis.

"Hashem left aside all of the mountains and hills, and rested his presence on [the lowly] Har Sinai [when he gave us the Torah]"

(Sota 5a)

"Said R. Channina bar Iddy, 'Why are the words of Torah compared to water, as it says "Let all who are thirsty go to the water" (Yeshayah 55:1)? To tell us that just as water leaves the higher places and flows to the lower places, so too, the words of Torah only remain in a person who has a humble spirit.' Rav Oshia said, 'Why are the words of Torah compared to three liquids: water, wine, and milk? To tell you that just as these three liquids are best kept in the cheapest of vessels (clay jugs) so too the words of Torah only remain in a person who has a humble spirit.' "

(Ta'anis 7a)

"What does it mean, 'And from the desert, [to] Matana; and from Matana, [to] Nachaliel' (Bamidbar 21:19)? ...When a person makes himself as a desert, that is trampled upon by all, then Torah is given to him as a present (~Matana) ...'Your wild animals rested there,' (Tehillim 68:11) ...if a person makes himself like a wild animal...that will eat t anything (that is, he isn't arrogantly particular about having his food cooked just right- Rashi) ...his learning will remain with him."

(Eruvin 54a)

" 'It (the Torah) isn't in the heaven, nor across the sea' (Devarim 30:12). Said Rava, [this means to say,] you won't find it in one who raises his pride with it to the heavens, or in one who broadens his pride with it, as wide as the sea (=indulges in worldly pleasures)"

(Eruvin 55a)

"They sent a message from [the Yeshivot in] Eretz Yisroel saying, ...'Take care with the children of the poor, for it is from them that Torah will spread (because they have a humble spirit-Ran)' "

(Nedarim 81a)

As my Rebbi, Rav Yisroel Zev Gustman, Zatza"l, used to say, "We pray, 'May my soul be to all like dust, open my heart to your Torah' (prayer following the Shemona Esrei prayer, see also Berachot 17a). Making our soul like dust is a necessary prerequisite for opening our heart to Hashem's Torah!"

If so, humility is clearly a trait we must work on before receiving the Torah on Shavuot.

Which particular trait of the Yetzer Hara is Chametz hinting to? Perhaps the trait of arrogance. The Sefer Hachinuch (Mitzva 117) explains that Se'or wasn't allowed to be brought on the Mizbe'ach, because it rises, bringing to mind arrogance, and the Pasuk tells us that the arrogant are the abomination of Hashem (Mishlei 16.5-see also Midrash Lekach Tov in Vayikra 2:11 for a corroborative D'rash). On Pesach, we teach ourselves to uproot any arrogance from our souls. Eating Matzo, the "poor man's bread" (Shemot 12: - alternate reading: "the *humbling* bread") imbues us with a humbled spirit.

This will neatly account for the unusual stringency of the prohibition of Chametz on Pesach. Unlike other prohibited foods, even if a *drop* of Chametz is mixed into a large bowl of non-Chametz food, the entire mixture becomes prohibited. Chametz isn't nullified after being mixed with 59 times its volume in permissible food. The Radvaz (responsum 977) suggests that we can understand this allegorically, as Chametz represents the Yetzer Hara, which must be entirely uprooted. According to our interpretation, that what is referred to here is the Yetzer Hara of arrogance, a parallel to this can be found in Sota 5a, "Said Rav Nachman bar Yitzchak, "None of it (arrogance), not even a bit of it [is good]" (See Rambam De'ot 2:4).

This humbling of our spirit is exactly what we need to prepare us for the Torah of Shavuot. If so, the countdown of the Omer can be seen as the period of preparation for receiving the Torah (see a hint of this idea also in Chinuch Mitzva # ??, Ra"n end of Pesachim in the name of Midrash). This period starts after the first humbling day of Pesach (the eve of the second day of the holiday). In order to start off this lesson in humility, we distance ourselves from any Chametz for an entire week, after which it is possible for us to continue developing our humility even after returning to Chametz (in keeping with the Rambam's advice -Hilchot De'ot 2:3- for uprooting unwanted characteristics: first you must bend to the opposite extreme, before you can return to the "middle" road safely).

After seven weeks of practice, we can totally conquer our arrogance, so that it is only used in the ways that are necessary for the service of Hashem. This may be symbolized by the bread offering we bring with the sacrifices of Shavuot- the only offering that accompanies a Korban, which is brought from Chametz (Menachot 58a- by the way, D'vash, which the Chinuch similarly compares to the arrogant, is also brought to the Mizbeach on Shavuot, in the form of Bikkurim- see Menachot Ibid).

This may also explain why the students of Rabbi Akiva stopped dying on Lag Ba'omer. According to the Kabalistic tradition, the seven weeks between Pesach and Shavuot correspond, successively, to the 7 "lower" Midot (characteristics; approaches) of the ten Midot with which Hashem conducts the world. Since the Midot are intertwined, each one encompasses all of the others within its realm. Therefore, each of these seven Midot can itself be divided into seven parts. During each day of the Omer, we are able to develop in ourselves a Midah that corresponds to the Midah and the sub-Midah of that particular day.

Following this tradition the week of Lag Ba'omer is the week of Hod (glory, grandeur). The day of Lag Ba'omer is the day corresponding to Hod in the week of Hod. As the name Hod implies, the day of Lag Ba'omer is fated to develop the positive aspects of pride, such as the one suggested by the Pasuk, "His heart was proud in the ways of Hashem" (Divrei Hayamim II 17:6).

If so, it is appropriate that on that day any positive aspects that accompanied the arrogance that Rebbi Akiva's students showed in their Torah were emphasized (after all, since they were great scholars. they undoubtedly *meant* to use their pride for increasing the honor of Hashem). This may be why the plague which affected the students who "didn't show respect one to the other" ceased on Lag Ba'omer, the day reserved for reveling in the pride and glory of the Torah.