Meditation is complete only by validating everything with Iswara's presence in ones life. Without accepting Iswara as the order one cannot find a place to surrender (samarpanam).Guru is the one who reveals it by unfolding the true nature of Iswara. Gurus words in keeping with pramana becomes the source of this wisdom. What the teacher ( guru ) says is important for the student ( Shishya ) but what the shishya doesn't say is important for the Guru. Interaction through proper questions and valid answers is the basis for the clarity of knowledge and this happens when the shishya has proximity to his/her Guru. The teaching tradition therefore calls it the "upanisadVidya" wisdom of the upanisads. This is taught in Bhagavad Gita also when Bhagavan Sri Krishna was asked by Arjuna who was an accomplished person but sarrow of life is following like a shadow and he realized it.So he sought the final answer for the human problem of self non-acceptance.SriKrishna taught him elaborately with karma yoga as the yoga of attitudes for managing raga and dvesha for gaining this knowledge. upanisads being the source which came through Rishis who revealed the vision and known as Vedas. Vedas being the body of knowledge which talks about the ultimate vision regarding the reality of the world and existence as such and known as Vedanta. Vedanta is the subject matter of upanisads and being ultimate knowledge placed appropriately towards the end of Vedas. It is the means of knowledge (pramana) for knowing the self. Without self knowledge there is no possibility of reaching anywhere in the search for the realities regarding this world or oneself.