LEV867 A regular Kohen shall not bring spiritual impurity upon himself except in limited circumstances. Owing to the fact that He has chosen the Kohanim to serve in the Beis HaMikdash, Hashem distances them from corpses. ... spiritual impurity is a damaging force, and when a Jew dies the spiritual impurity that rests on the corpse is very strong. Much more potent than any other type of spiritual impurity, it is called “the father of the fathers of spiritual impurity.” When a Jew dies, his intelligent and Divine soul departs from his body, leaving behind only his physical body, whose only desire was the lowly, evil and mundane. Even during the person's lifetime his body constantly strove to lead him to sin and sully his precious soul. Accordingly, when the soul--the sublime glory of the body--departs and all that remains is the base and material flesh, it stands to reason that the corpse defiles everything around it. For this reason, it is fitting that Kohanim--Hashem's servants in the Beis HaMikdash--be kept at a distance from this strong spiritual impurity. When certain close relatives of the Kohen die, however, the Torah--for the Kohen’s benefit--allows the Kohen to render himself impure, “for the ways of the Torah are pleasant, and all of Its paths are peace.” The Torah does not want to cause any Kohen excessive suffering. When the heart of a Kohen is aggrieved over the loss of a loved one--someone of his own flesh--the Torah does not forbid him to enter the tent of the deceased to give vent to his grief and weep bitterly over his loss.