The Torah commands us to count seven weeks from the day of the Omer offering on the second day of Pesach to Shavuot. It should be a period of joy and anticipation as we move from the Exodus from Egypt to receiving the Torah.
However, by the Middle Ages, we find many rabbis ruling that the Omer is a period of mourning for the death of Rabbi Akiva’s 12,000 pairs of students. They died, according to the Talmud (Yevamot 62b), in a plague as a punishment “because they did not behave toward each other with respect.”
Rabbi Akiva’s students may have studied a lot of Torah, but they missed the fundamental principle of treating each other with dignity.
As we move toward receiving the Torah on Shavuot, we refrain from going to concerts, getting haircuts and going to weddings, as a reminder of the cost of the lack of unity.