The om (omkara) represents the Supreme (Chapter 10 Text 25)
- Hare Krishna Friends,
maharsinam bhrgur aham
giram asmy ekam aksaram
yajnanam japa-yajno 'smi
maha-rsinam--among the great sages; bhrguh--Bhrgu; aham--I am; giram--of vibrations; asmi--I am; ekam aksaram--pranava; yajnanam--of sacrifices; japa-yajnah--chanting; asmi--I am; sthavaranam--of immovable things; himalayah--the Himalayan mountains.
Of the great sages I am Bhrgu; of vibrations I am the transcendental om. Of sacrifices I am the chanting of the holy names [japa], and of immovable things I am the Himalayas.
Brahma, the first living creature within the universe, created several sons for the propagation of various kinds of species. The most powerful of his sons is Bhrgu, who is also the greatest sage. Of all the transcendental vibrations, the om (omkara) represents the Supreme. Of all sacrifices, the chanting of Hare Krsna, Hare Krsna, Krsna Krsna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare is the purest representation of Krsna. Sometimes animal sacrifices are recommended, but in the sacrifice of Hare Krsna, Hare Krsna, there is no question of violence. It is the simplest and the purest. Whatever is sublime in the worlds is a representation of Krsna. Therefore the Himalayas, the greatest mountains in the world, also represent Him. The mountain named Meru was mentioned in a previous verse, but Meru is sometimes movable, whereas the Himalayas are never movable. Thus the Himalayas are greater than Meru.
Source As It Is by HDG. A.C. BhaktiVedanta Swami Srila Prabhupada