 The discussion of the dead in the profession associated with tithing, is one of a series of passages setting out the teaching that contact with the dead is antithetical to purity.In God instructed Moses to direct the priests not to allow themselves to become defiled by contact with the dead, except for a mother, father, son, daughter, brother, or unmarried sister.And the priests were not to engage in mourning rituals of making baldness upon their heads, shaving off the corners of their beards, or cutting their flesh.