Praśna Upaniṣad · 6..3
तद्वै तदुक्तं स्तोत्रं वा स्तुतिर्वेति सर्वाणि ह वा एतानि भूतान्युक्त्वा स्तोत्रं युजन्ते स यस्तद्वेदयते यथोक्त्वा स्तोत्रं युज्यते
tadvai taduktaṃ stotraṃ vā stutirveti sarvāṇi ha vā etāni bhūtānyuktvā stotraṃ yujante sa yastadvedayate yathoktvā stotraṃ yujyate
That, verily, is called a stanza, or a hymn of praise. All these beings, having sung, unite in the hymn. Whoever knows this, knows how, having sung, they unite in the hymn.
The universe is a stotra — a hymn of praise to Prāṇa. All beings (bhūtāni), by “singing” (by expressing their existence), unite (yujyante) in this cosmic hymn.
Yuj — the same root as yoga. Yoga is union, and here all beings unite in the great hymn of Prāṇa.
Sa yaḥ tat vedayate — “whoever knows this.” The knowledge is not merely intellectual, but participatory — knowing how one unites to the cosmic hymn, how one becomes part of the universal praise.
Each breath, each heartbeat, each action is a note in this hymn. The yogī learns to sing consciously, knowing that they are not a soloist but part of the universal chorus.