Why Must We Treat a Dead Body with Respect?
Halacha distinguishes between Tashmishei Mitzvah (items with which a person performs a mitzvah, e.g. – tzitzit, lulav, succah, etc.) and Tashmishei Kedusha (items which involve scriptural writing, e.g. – Sefer Torah, tefillin, mezuzah, etc.). After Succot, a person may theoretically throw out his lulav and etrog. The law is that Tashmishei Mitzvah do not retain sanctity; after the completion of their use for the mitzvah performance, a person may discard them. (There is a nice custom to use the Lulav to burn the Chametz before Pesach, but this is only a custom and not a fundamental requirement.) Tashmishei Kedusha, however, remain eternally holy — even after the completion of their service in the performance of a mitzvah. Even if a Sefer Torah or tefillin falls into the water and becomes ruined, their sanctity remains forever.
The law of Tashmishei Kedusha prevails to such an extent that even items used as accessories to an item containing Torah verses (such as a cloth covering for a Sefer Torah) have sanctity even after they have become worn out and must be buried rather than simply discarded.
What is the difference? The difference is that Tashmishei Mitzvah no longer retain holiness once the mitzvah is finished. However, when the Name of G-d and words of Torah are written on parchment, the holiness remains forever.
This is why a human body has sanctity even after death. Every Jew is a vehicle for words of Torah. Just as parchment becomes holy forever, so too the body of a Jew — who spoke words of Torah and who said the words Shema Yisrael — becomes like a Sefer Torah. Therefore, even though the soul has departed, the words of holiness that were “inscribed” on that body during its lifetime lend an eternal kedusha to that body, forever and ever. (adapted from Rabbi Yissocher Frand on torah.org)
The law of Tashmishei Kedusha prevails to such an extent that even items used as accessories to an item containing Torah verses (such as a cloth covering for a Sefer Torah) have sanctity even after they have become worn out and must be buried rather than simply discarded.
What is the difference? The difference is that Tashmishei Mitzvah no longer retain holiness once the mitzvah is finished. However, when the Name of G-d and words of Torah are written on parchment, the holiness remains forever.
This is why a human body has sanctity even after death. Every Jew is a vehicle for words of Torah. Just as parchment becomes holy forever, so too the body of a Jew — who spoke words of Torah and who said the words Shema Yisrael — becomes like a Sefer Torah. Therefore, even though the soul has departed, the words of holiness that were “inscribed” on that body during its lifetime lend an eternal kedusha to that body, forever and ever. (adapted from Rabbi Yissocher Frand on torah.org)