In a torah.org dvar torah from Rabbi Frand, he quotes a 'famous saying from the Gaon of Vilna'.
There is a famous saying from the Gaon of Vilna: If the wood used in the ax handle used to chop down trees used to build a Beis HaKeneses came from a tree planted by a Shomer Shabbos Jew, people would never recite a prayer without Kavannah (intense devotion) in that shul.
Where can I find the original source for this quote?
