Why is Lag b’Omer celebrated with bonfires and bows and arrows?
by Rabbi Yossi Marcus
The bonfires celebrate the immense light that was brought into the world by Rabbi Shimon bar Yochai [who passed away on Lag b’Omer], especially on the day of his passing.
The bow commemorates the fact that during Rabbi Shimon’s lifetime no rainbow was ever seen. [Bereishit Rabbah 35:2] Note: This was a good thing because the rainbow appears when the earth deserves punishment. The first time a rainbow appeared was after Noah’s flood, when G-d said that He will no longer destroy the world, rather He would send a sign: the rainbow. During Rabbi Shimon’s lifetime, the world was filled with merit because of him and therefore never saw a rainbow. [Genesis 9:8-17 and Rashi there]
There is a Kabbalistic tradition that on Lag b’Omer a rainbow will appear in a different color, which will symbolize the arrival of the Messianic age [Bnei Yissaschar]