Praśna Upaniṣad · 6..2

यथा वै कश्चित्साम प्रवदन्नभिप्रवदत्येवं प्राणो वै साम तद्यद्यत्साम तद्वाण्मयमेव तद्वाचि प्रतिष्ठितम्

yathā vai kaścitsāma pravadannabhipravadyevaṃ prāṇo vai sāma tadyadyatsāma tadvāṇmayameva tadvāci pratiṣṭhitam

As when someone sings the Sāman with enthusiasm, thus Prāṇa is, verily, the Sāman. That which is the Sāman, that is made of speech; in speech it is established.

The Sāman is the Veda of chants, melodies that elevate consciousness. One who sings the Sāman with abhipravāda (enthusiasm, elevation) experiences an unfolding of energy.

Thus is Prāṇa — a continuous unfolding, a cosmic melody. The Sāman is vāṅmaya — “made of speech” (vāc). And vāc is established in Prāṇa.

The sequence is: Prāṇa → Vāc → Sāman → all worlds.

Prāṇa is the basis, vāc is the expression, and the Sāman is the melodic elevation that leads to realization.

For the yogī: the prāṇa must have the rhythm and melody of the Sāman — elevated, harmonious, leading upward. The practice of prāṇāyāma is not mechanical; it is a sacred song of the body.