Answer:
   
   Jews normally bury the dead within 24 hours, however, there are
   exceptions. A funeral could be held up for a day or two if it would
   save a mourner the additional pain of missing the funeral. Second, we
   do not bury people on the Sabbath or any of the holidays on which work
   is prohibited.
   
   Why do Jews do this? The most straightforward reason is that the Torah
   says so. In discussing capital punishment, the Torah says the body
   must be buried before nightfall. And if a murderer deserves that much,
   so ought any deceased person.
   
   But this isn't enough? Why might there be this commandment? It's
   considered disrespectful toward the dead to leave the body unburied.
   Perhaps it's because it means people will witness the body's decay, or
   see and remember something that seems like the person, but is
   inanimate and without fears or dreams. There is a second reason, based
   on kabbalah. During the course of a lifetime, a soul forms an
   attachment to the body. Part of the punishment for sins comitted out
   of a pursuit of the physical is the subsequent disillusionment with
   the body and with the values that lead to that pursuit. This is called
   "chibut haqever" (attachment to the grave). Burial hastens the end of
   this punishment, by bringing the soul "closure" in its relationship to
   the body. It is therefore merciful to the deceased to bury as soon as
   possible.