AVŚ 8.9.3
यानि त्रीणि बृहन्ति येषां चतुर्थं वियुनक्ति वाचम् । ब्रह्मैनद् विद्यात् तपसा विपश्चिद् यस्मिन्न् एकं युज्यते यस्मिन्न् एकम् ॥३॥
yāni trīṇi bṛhanti yeṣāṃ caturthaṃ viyunakti vācam | brahmainad vidyāt tapasā vipaścid yasminn ekaṃ yujyate yasminn ekam ||3||
Devanagari rendered by HREEM from the edition's roman (IAST) text; the IAST is the edition's own.
What three great ones (bṛhát, n.) there are, the fourth of which [one] disjoins [as] speech—the priest (brahmán) may know it by penance, the inspired one, in which one (ékam) is joined, in which one [is joined].
Translated by William Dwight Whitney (1905)