"...and Bilaam, the son of Beor, they killed by the sword." [31:8]
Rashi, Rabbi Shlomo Yitzchaki, says that Bilaam "attacked Israel, and
exchanged his own trade for theirs, for they [Israel] do not ascend except
with their mouths by way of prayer and requests. And he came and grasped
hold of their trade, in order to curse them with his mouth. They, too,
attacked him and exchanged their own trade for that of other nations, who
attack by the sword..."
Israel, as Rashi explains, did not fight like other nations. As many as
were sent to war, were sent to the House of Study, to study Torah and
request G-d's protection over His People. While everyone else was measuring
lengths of spears and numbers of arrows, Israel counted hours of study and
repeated prayers. The Medrash Socher Tov says "the mouths of Israel, that
is their sword, as it says 'and a two-edged sword [lit. sword of mouths] in
their hand.'" [Psalm 149:6]
Clearly he who wrote "the pen is mightier than the sword" did not have
words of prayer in mind, but nonetheless prayer and study have stood by
Israel while its neighbors have faded into history. Not only the pen, but
the mouth itself, has proven more effective.
The Chofetz Chaim, Rabbi Israel Mayer HaKohen Kagan of Radin, notes that
every craftsman takes good care of his tools - and we learn from Rashi that
the mouth is just as much of a tool as an M-16 is to a soldier. So, like
every craftsman, we must take good care of this tool, and be certain not to
'ruin' it with forbidden speech like gossiping, falsehood and angry words.
Rather, we should work to 'sharpen' it with words of Torah and prayer!