Mbh 14.21.4

"'"The Brahmana said, 'Know that I have two minds, immovable and movable. That which is immovable is, verily, with me; the movable is in your dominion.[59] That mind is verily called movable which, in the form of Mantra, letter, or voice, is referable to your dominion. Hence, thou art superior (to the other mind which concerns itself with only the external world). But since, coming of thy own accord, O beautiful one, thou enterest into the engagement (about the fruition of all wishes), therefore, filling myself with breath, I utter thee.[60] The goddess Word used always to dwell between Prana and Apana. But, O blessed one, sinking into Apana, though urged upwards, in consequence of becoming dissociated from Prana, she ran to Prajapati and said,--Be gratified with me, O holy one.--The Prana appeared, once more fostering Word. Hence, Word, encountering deep exhalation, never utters anything. Word always flows as endued with utterance or unendued with it.[61] Amongst those two, Word without utterance is superior to Word with utterance. Like a cow endued with excellent milk, she (Word without utterance) yields diverse kinds of meaning. This one always yields the Eternal (viz., Emancipation), speaking of Brahman. O thou of beautiful smiles, Word is a cow, in consequence of her puissance which is both divine and not divine. Behold the distinction of these two subtle forms of Word that flow.'[62]