ramban - end of sukkos - atzeres- speaks in riddles about days of sefirah... yesod v'shoresh says don't bother with kavonos, too deep for most. Rather be aware the words you're about to say do tremendous things....
This shows that the power of speech - even without even understanding what's going on - has huge effects! Kal v'chomer when we do understand - words of tefilah, chizuk or pain....
