The Upaniṣads are not simply textbooks of an intellectual nature, but are sacred documents that contain faithful writings of the mystical experiences and wisdom of the ancient seers or Vedic ṛṣis. This transforms them into transcendental road maps of priceless value for seekers of the Truth. As footsteps of the great sages who traveled the path to the light, they are worthy of following. They are not only a means of information, but transformation.

The meaning of the word upaniṣad is very beautiful; it means, "to sit close", to sit close to the closest to you... which is you... they are literary testimonials of those who have realized their soul...

The Upaniṣads are the wisdom of the Self... You can get infected with it by sitting close to and taking refuge under the lotus feet of a spiritual master. This is our tradition...

Many of the books in the world that are considered to be sacred were actually written by religious people commenting on what they had heard about the utterances of enlightened beings. A major part of the Upaniṣads' value is due to their forming direct testimonials and documentation of the words of beings who have experienced and realized the reality of the soul. In this respect, they are scriptures of incalculable spiritual value, because they were not written to or destined for a specific group of people in a particular time or place. The Upaniṣadic vision is nonsectarian. The enlightened one does not see countries, races or nations, but he sees the one humanity. Therefore, this is a message for all men, in all places and all times...

When referring to the author or authors of the different Upaniṣads, it is important to clarify that the prevailing attitude in Hinduism, as in science, is that more important than the one "who discovers" something, is "what" has been discovered, and more important than "who" is the expounder of certain revelations, is "what the revelation consists of". This sometimes leads to some confusion, especially for western students and readers, due to the fact that in our culture, the approach of certain religious organizations has been to situate religion more closely to history and archeology than to the direct realization of the Divine and enlightenment...

In the first chapter of Muktitkā Upaniṣad (verses 30 to 39), there is a list of the main 108 Upaniṣads, in which Īśopaniṣad occupies first place, which locates it in an exalted position within Adwaita literature. Although the Īśopaniṣad or Īśavasya Upaniṣad is one of the smallest books, having only 18 verses, it is considered to be one of the most authoritative teachings of the Vedic scriptures, or śruti, by some of the most important classical, traditional and orthodox lineages within Hinduism.

We find the Īśavasya Upanisad in the last adhyāya, or final chapter of Śukla Yajur—Veda Saṁhitā. Another name by which this book is known is the Saṁhitopaniṣad, because it is part of the Saṁhitā, or the collection of mantras pertaining to the ritualistic section of the Veda or Karma Kanda.

The name of this work, Īśa, is derived from its first verse, Īśāvāsyam idam sarvam, which also contains one of its most important messages: although we think that when we die we leave all our belongings, possessions, our achievements and our beloved ones, in fact, we do not leave anything, because absolutely everything belongs only to the Divine, and because besides God, nothing really exists here. It is appropriate to emphasize that this Upaniṣad, also called the Vājasaneyi Upaniṣad, although small in volume, is essential for the study of Hinduism in general, and particularly for the study of Vedānta. Many of the greatest truths that are pillars of the Adwaita Vedānta have come from this most valuable text.

Yogācārya Bhaktivedānta Rāmakṛṣṇānanda Swāmī Mahārāja