Mandukya Karika, verse 4.84

Sanskrit text, IAST transliteration and English translation

कोठ्यश्चतस्र एतास्तु ग्रहैर्यासां सदाऽऽवृतः ।
भगवानाभिरस्पृष्टो येन दृष्टः स सर्वदृक् ॥ ८४ ॥

koṭhyaścatasra etāstu grahairyāsāṃ sadā''vṛtaḥ |
bhagavānābhiraspṛṣṭo yena dṛṣṭaḥ sa sarvadṛk || 84 ||

84. These are the four alternative theories regarding (the nature of) Ātman, on account of attachment to which It always remains covered (from one’s view). He who has known that Ātman is ever-untouched by any of these (predicates) indeed sees all.

Shankara Bhashya (commentary)

What is the nature of the essence, i.e., the Ultimate Reality, by knowing which people are purged of their stupidity and are really made to attain to wisdom?

It is thus replied:—There are four alternate theories regarding Ātman such as, It exists, It does not exist, etc., mentioned in the works of those who are fond of disputations. The Ātman always remains covered and hidden from these vain talkers on account of their attachment to their theories. The thoughtful person who has realised the Ātman, known only by the (correct understanding of) Upaniṣads, as ever-untouched by any of the four alternative predicates such as It exists,. It does not exist, etc., is the seer¹ of all, the omniscient and the real knower of the Ultimate Reality.

Anandagiri Tika (glossary)

¹ Seer of all—All that exists is Ātman. Therefore one who knows Ātman knows all. There remains nothing else to be known by him.