In the Upanishads there are certain passages which are called the great words,1which are always quoted and referred to.
In Him, that One — in Him alone, the Atman — exist all other worlds. What is the use of all other talk? Know Him alone. This is the bridge over this life to reach universality.
He [Angiras] goes on to show a practical way. So far it is very figurative.
Just as all the spokes of a wheel meet at the axle, even so in this body is that place from which all the arteries flow andat which they all meet. There, meditate upon the Om that is in the heart. May thou succeed.
May the gentle one with success attain the goal. May you go beyond all darkness to Him who is omniscient, the All-Knowing. His glory is in heaven, on earth and everywhere.
He who has become the mind, the Prânâ, He who is the leader in the body, He who is established in the food, the energy of life. By supreme knowledge the sages see Him whose nature is bliss, who shines as immortality.( Mundaka Upanishad 2.2.8.)
Complete Works of Swami Vivekananda, Volume IX
