CHĀNDOGYA UPANISHAD · 3.2.2

तानि वा एतानि यजूंष्य् एतं यजुर्वेदम् अभ्यतपन् ।
तस्य अभितप्तस्य यशस् तेज इन्द्रियं वीर्यम् अन्नाद्यं रसो ऽजायत ॥

tāni vā etāni yajūṃṣy etaṃ yajurvedam abhyatapan ।
tasya abhitaptasya yaśas teja indriyaṃ vīryam annādyaṃ raso ’jāyata ॥

Those very Yagus verses (as bees) brooded over the Yagur-veda sacrifice (the flower); and from it, thus brooded on, sprang as its (nectar) essence, fame, glory of countenance, vigour, strength, and health.

F. Max Müller · The Upanishads, Sacred Books of the East 1 (1879)