BṚHADĀRAṆYAKA UPANISHAD · 5.13.3

साम ।
प्राणो वै साम ।
प्राणे हीमानि सर्वाणि भूतानि सम्यञ्चि ।
सम्यञ्चि हास्मै सर्वाणि भूतानि श्रैष्ठ्याय कल्पन्ते ।
साम्नः सायुज्यं सलोकतां जयति य एवं वेद ॥

sāma ।
prāṇo vai sāma ।
prāṇe hīmāni sarvāṇi bhūtāni samyañci ।
samyañci hāsmai sarvāṇi bhūtāni śraiṣṭhyāya kalpante ।
sāmnaḥ sāyujyaṃ salokatāṃ jayati ya evaṃ veda ॥

Next follows the Sâman. Verily, breath is the Sâman, for all these beings meet in breath. For him who knows this, all beings meet to procure his excellence; he obtains union and oneness with the Sâman.

F. Max Müller · The Upanishads, Sacred Books of the East 15 (1884)