Bhagavad Gita 13.12
ज्ञेयं यत्तत्प्रवक्ष्यामि यज्ज्ञात्वामृतमश्नुते। अनादिमत्परं ब्रह्म न सत्तन्नासदुच्यते॥
jñeyaṁ yat tat pravakṣyāmi yaj jñātvāmṛtam aśnute anādi mat-paraṁ brahma na sat tan nāsad ucyate
Translation
I will declare what is to be known, knowing which one attains the immortal. Beginningless, supreme brahman; it is called neither being nor non-being.
Reflection
Sit one minute with what language cannot reach. Let the silence be the answer.
Read this verse in its chapter: Chapter Thirteen
Field done. Knowledge-qualities done. Now the object of knowledge. The promise is direct: knowing this, one attains the deathless. Anadi, beginningless. Mat-param, supreme to me. Brahman. And then the famous double negation: it is not called sat, nor asat. Existent does not fit because existence is a category for things inside time. Non-existent does not fit because brahman is the substrate of every existing thing. Language fails at the edge. The traditional Upanishadic strategy: name by negation, point by what cannot be said. The verse does not apologize for this. It is announcing the kind of object the inquiry now turns toward. Not a thing. Not a non-thing.