The unreal has no being; the real never ceases to be. The truth about both has been seen by the seers of the Truth.
In simple words
Krishna tells Arjuna a fundamental truth: "What is unreal never truly exists. What is real never stops existing. The people who see clearly understand this difference."
नnotअसतःof the unrealविद्यतेisभावःbeingनnotअभावःnonbeingविद्यतेisसतःof the realउभयोःof the twoअपिalsoदृष्टः(has been) seenअन्तःthe final truthतुindeedअनयोःof these
Contemporary scholarly and practical interpretations for modern seekers.
Swami Sivananda
2.16 न not? असतः of the unreal? विद्यते is? भावः being? न not? अभावः nonbeing? विद्यते is? सतः of the real? उभयोः of the two? अपि also? दृष्टः (has been) seen? अन्तः the final truth? तु indeed? अनयोः of these? तत्त्वदर्शिभिः by the knowers of the Truth.Commentary -- The changeless? homogeneous Atman or the Self always exists. It is the only solid Reality. This phenomenal world of names and forms is ever changing. Hence it is unreal. The sage or the Jivanmukta is fully aware that the Self always exists and that this world is like a mirage. Through his Jnanachakshus or the eye of intuition? he directly cognises the Self. This world vanishes for him like the snake in the rope? after it has been seen that only the rope exists. He rejects the names and forms and takes the underlying Essence in all the names and forms? viz.? AstiBhatiPriya or Satchidananda or ExistenceKnowledgeBliss Absolute. Hence he is a Tattvadarshi or a knower of the Truth or the Essence.What is changing must be unreal. What is constant or permanent must be real.
Swami Chinmayananda
This interpretation draws on a specific tradition and may not represent the view of any single school. For authoritative guidance within a specific tradition, seek a qualified teacher.
# BG 2.16 — The Distinction Between the Real and the Unreal
In the Vedantic scriptures, the discrimination between the Real and the Unreal is conducted with utmost scientific precision. Our philosophical tradition provides definitions for both. The Unreal is that which had no existence in the past and shall have none in the future, yet appears to exist in the present. In the language of the Mandukya Karika, that which has no existence at its beginning and end does not truly exist even in the present. Objects that appear before us, though illusory, are nonetheless regarded as real in conventional understanding. Naturally, the Real is that which remains eternally unchanging throughout past, present, and future—all three dimensions of time. In ordinary experience, if a person mistakes a pillar for a ghost, the ghost is deemed unreal from the pillar's perspective, for the ghost is impermanent and vanishes upon recognition of the pillar. Similarly, upon waking from sleep, we feel no concern for the children of our dream, for awakening reveals the illusory nature of the dream. Though the dream appeared real, it was false. Therefore, only that which remains uncontradicted throughout all three periods of time is called the Real.
Our life is confined within these three inert instruments—body, mind, and intellect—for the experiences derived through them of external objects, feelings, and thoughts are momentary. Constant transformation occurs within all three. The cessation of one state is the birth of another. By definition, all these are unreal. Yet is there not something Real behind them? There is no doubt that the countless changes occurring in objects require some unchanging substratum, some eternal support. To hold together the innumerable experiences occurring at the levels of body, mind, and intellect, and to grant the experience of one complete life, there must surely be an eternal, immutable Real substance as the foundation.
Within us exists something like a single thread that holds precious gems—something that, amidst all changes, binds together diverse experiences into one coherence. Upon subtle reflection, this knowledge shall dawn: that something is the consciousness-nature of one's own Self, the atman. The countless experiences that have been illumined—none of these experiences is the atman itself. Life, which is a stream of experiences, becomes possible only through this consciousness. It is this consciousness that illumines the experiences of childhood, youth, and old age. Experiences come and go. That consciousness through which I have known all things, without which I have no existence whatsoever—that consciousness, the atman, is free from birth and death, eternal, the true Real.
The seers of Truth recognize the essence of both—the Real and the Unreal, the atman and the non-atman. From the mysterious union of these two, this wondrous universe arises.
Now, what is that eternal Real substance? Listen.