The Torah in Parashat Emor (Vayikra 23:3) commands that a Kohen must become Tameh (impure) in the case of the passing of an immediate family member. Although Kohanim are generally required to avoid Tum’at Met (the impurity resulting from contact with a human corpse), they are specifically obligated to tend to the burial of immediate family members. In fact, the Safra tells of a Kohen named Yosef whose wife passed away on Ereb Pesach, and he did not want to tend to the body, because he would then become Tameh and thus be unable to offer the Pesach sacrifice. The Rabbis forced him to tend to the body, in fulfillment of the Biblical command. The Rambam points to this verse as the source of the general obligation of Abelut – to observe a day of mourning for a deceased family member. The Torah introduced this Misva in the specific context of Kohanim to underscore the fact that even a Kohen, who normally must avoid Tum’at Met, is required to become Tameh in the case of a deceased family member. All the more so, non-Kohanim are required to involve themselves in the burial of family members and observe a day of mourning. Proof that Abelut constitutes a Torah obligation may be drawn from the Gemara’s discussion concerning the suspension of Abelut on Yom Tob. The celebration of Yom Tob overrides Abelut, the Gemara explains, because Yom Tob constitutes an “Aseh De’rabim” – an affirmative command binding upon the entire nation – whereas mourning constitutes an “Aseh De’yahid” – a command binding upon just one individual. The Gemara here explicitly refers to Abelut as an “Aseh” (affirmative command), clearly demonstrating that it regarded mourning as a Biblical obligation. The Torah obligation of Abelut requires observing just one day of mourning – the day of the burial – but the Sages enacted a seven-day period of Abelut. The Sefer Ha’hinuch writes that the Torah introduced the obligation to mourn a deceased family member because “a person is affected by his actions,” and thus mourning practices will lead him to reflect and contemplate the painful loss he has suffered. He will realize that this has befallen him because of his misdeeds, and he will thus be stirred to repent and improve his conduct. The Sefer Ha’hinuch emphasizes that whereas the non-believers dismiss death as a natural occurrence, we are to recognize that everything that happens has been ordained by G-d. And thus after the loss of a loved one, the Torah requires a person to mourn and contemplate his loss so he is driven to repent. As mentioned, the Torah obligation of mourning applies only for one day, and it begins only after the burial. In the case of a “Nefel” – an infant who died within thirty days of birth, Heaven forbid – mourning is not observed, unless it has been determined that the baby was born after a full-term pregnancy. The Sefer Ha’hinuch writes that after the death of certain types of wicked people, mourning is not observed, as their deaths are actually cause of celebration. These include a “Moser” – somebody who reports on his fellow Jews to hostile gentile authorities so they can confiscate their property or imprison them – and those who defect and marry out of the faith. The obligation to mourn a deceased family member applies to both men and women, and in all times and all places.