This Upanishad belongs to the Atharva Veda. As the name of the Upanishad suggests, the teachings revealed in it are such as to leave its students clean, like a shaven head (mundaka), rid of the veil of ignorance. The lucid translation of the text along with Shankaracharya's commentary on it is an additional aid to comprehend the profundity of the subject.
Your Atman is the support of the universe -- whose support do you stand in need of? Wait with patience and love and strength. If helpers are not ready now, they will come in time. Why should we be in a hurry? The real working force of all great work is in its almost unperceived beginnings.
-Swami Vivekananda