Advayataraka Upanishad Mandalabrahmana Upanishad

These upani¿ads advocate the path of T¿raka Yoga to attain kaivalya, final liberation.
Advaya-T¿raka-Upani¿ad is the upani¿ad of the non-dual (advaya) deliverer (t¿raka). In the context of T¿raka Yoga 'taraka' means 'ferrying one across the ocean of säs¿ra', liberation from the cycle of birth, death and rebirth, by dwelling in the radiant light of pure consciousness, which is the central theme of Ved¿nta philosophy, the identity of the Brahman with the innermost Self, the ¿tman.
The text begins by listing the six spiritual qualities necessary for progress on the spiritual path. It then describes the three points of concentration (laksyas), outer, intermediate and inner, each one giving insights, signs or visual experiences.
Mä¿ala-Br¿hmäa-Upani¿ad is a later, more extensive version. It describes the five types of 'ether-space' (¿k¿¿a) known in t¿raka-yoga, the three types of gaze (d¿¿¿i) during meditation and the importance of the nine cakras and six ¿dh¿ras. The goal is 'transmindedness' (amanaskat¿), the condition of 'living liberation' (j¿van-mukti). The yogin must follow the eightfold path of yoga, conquering any obstacles with his spiritual qualities.
Meditation on T¿raka through ¿¿mbhav¿ mudr¿ leads to präava, the light of pure consciousness and the primal sound vibration of AUM. The mind is thus recognised as the cause of both bondage and liberation. Finally the yogin becomes an avadh¿ta, free from all worldly attachments or mental illusions.