Guarding the Tongue
Rav Yehuda Zev teaches that a home where shemiras haloshon is observed and studied is filled with kedusha. He explained that the Chofetz Chaim felt that most of the tzoros that befall Klal Yisroel come from failing to guard the tongue, and that shemiras haloshon draws down divine compassion for both the individual and the whole people. So whenever anyone asked him for a berocha, he urged that person to learn these halochos every day. It is said that every family that learns them according to the daily schedule will surely merit yeshuos.
Source: Teachings of the Manchester Rosh Yeshiva, as told in Yated Neeman (D. Sofer)