BṚHADĀRAṆYAKA UPANISHAD · 5.13.2

यजुः ।
प्राणो वै यजुः ।
प्राणे हीमानि सर्वाणि भूतानि युज्यन्ते ।
युज्यन्ते हास्मै सर्वाणि भूतानि श्रैष्ठ्याय ।
यजुषः सायुज्यं सलोकतां जयति य एवं वेद ॥

yajuḥ ।
prāṇo vai yajuḥ ।
prāṇe hīmāni sarvāṇi bhūtāni yujyante ।
yujyante hāsmai sarvāṇi bhūtāni śraiṣṭhyāya ।
yajuṣaḥ sāyujyaṃ salokatāṃ jayati ya evaṃ veda ॥

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

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