Laws of Mourning

The incident of the death of Nadav and Avihu teaches us some of the rules regarding אבלות, mourning. We learn this by way of אסמכתא, an indirect way to draw conclusions. Specifically, Aharon and his remaining sons, Elazar and Itamar, were told that despite their great loss, they were not to avoid cutting their hair, and they were not to tear their clothes. Based on this commandment, we can derive that normally, mourners are not supposed to cut their hair or shave. Similarly, doing קריעה, or tearing one’s clothes, is the appropriate behavior during one’s time of grief. There is still some debate as to whether קריעה is a Torah or Rabbinic law. In general, Halachot that are learned by way of אסמכתא, even though they are derived from the Torah, are still considered Rabbinical. Aharon and his sons were given special orders because of the dedication of the Mishkan to avoid normal mourning practices.