Once, Latu Maharaj (Swami Adbhutananda) went with Swami Shuddhananda, a disciple of Swami Vivekananda to listen to a class by Pandit Shashadhar on the Katha Upanishad. The pandit read the verse: “The Purusha (Inner Self), no larger than a thumb, always dwells in the hearts of men. Let a man separate Him from the body with perseverance, as one separates the tender stalk from a blade of grass” (2.3.17). As soon as Latu Maharaj heard this passage, he cried out repeatedly, “Sudhir, the pandit said right, the pandit said right”. Then, Swami Shuddhananda realized that he must have experienced that state himself, otherwise he could not have understood that abstruse Sanskrit Passage.

Source: God Lived With Them by Swami Chetanananda