Ayn Od Milvado

It is told that Rav Shapira related how, when the Griz came before the draft board and feared he would be taken into army service, his father, Rav Chaim, instructed him to use a segulah (a spiritual remedy) from the Nefesh HaChaim.

Rav Shapira also told, in the name of the Brisker Rav, that when the Rav escaped from Warsaw during World War II, the Nazis, may their names be erased, had already conquered half of Poland, and every road was swarming with murderers. All along the way he concentrated on this segulah without pause. Once, for a single moment, his concentration slipped, and at that moment a wicked Nazi attacked them. At once he returned his focus to the segulah of the Nefesh HaChaim, and they were saved.