The "Song of the Free", a classic text of Advaita Vedanta expresses the highest experience of the unfettered Self. Sanskrit text, transliteration and English translation. One of the purest statements of the supreme knowledge of Advaita, by a sage who lived over three thousand years ago.
Those who have succeeded in attaching or detaching their minds at will have succeeded in Pratyahara, which means gathering towards, checking the outgoing powers of the mind, freeing it from the thralldom of the senses. When we can do this, we shall really possess character; then alone we shall have taken a long step towards freedom. Before that, we are mere machines.
-Swami Vivekananda