The letter U, advancing from Vaiśvānara toward stability, its explanation is Taijasa. One who knows attains all stability and is no one’s enemy. The letter M, from Taijasa toward stability, its explanation is Prājña. One who knows becomes the foundation of all.

The final mantra completes the A-U-M triad with their respective promises of realization:

For U (Taijasa): vidvān bhavati sarvaṃ pratiṣṭhāṃ gacchati — one who knows U attains all stability (pratiṣṭhā). No longer “becomes manifestation” (as with A), but attains the foundation. Knowing the dream state means mastering the subtle world — dreams become no longer involuntary, unconscious impressions become illuminated.

Na ha kasyacid amitraḥ syāt: and is no one’s enemy. The realization of U dissolves hostility. One who understands the dream world understands that “others” are as much projections as dreams.

For M (Prājña): vidvān bhavati sarvasya pratiṣṭhā — one who knows M becomes the foundation (pratiṣṭhā) of all. It is the deepest realization within the three states: the condition of witness that sustains waking, dream and deep sleep.

The progression is precise:

• A → know manifestation (vyakti) → be all manifestation
• U → know subtlety (pratiṣṭhā) → attain all stability
• M → know unity (prājña) → become the foundation of all

But the Māṇḍūkya does not end here. The silence after A-U-M — the fourth state (turīya) described in mantra 7 — is the goal. The three are paths toward it. Sound ends; reality remains.

Sa ātmā, sa vijñeyaḥ — That is the Ātman. That must be known.