You may remember that when you read publicly from the Torah for your bar/batmitzvah, one follows the words on the scroll using a long, silver, ornate, pointing hand called a yad. So far as I can tell, the source for this custom is the Talmud ( Megillah 32a), which forbids touching the bare Torah with our hands. Using a yad instead of your finger hovering over the parchment makes it easier to avoid accidental contact. While not a strict requirement of Jewish law, using a yad is considered hiddur mitzvah, a beautification of the mitzvah.
In fact, the Talmud says, rather shockingly, that one who touches the naked Torah scroll will be buried naked. The ideas seems to be that if you disgrace the Torah by overexposing it, you too will be overexposed in a disgraceful way. The talmudic sage Abaye makes the statement less harsh by saying that it means you would be buried naked of this mitzvah of treating the Torah respectfully.