Shatapatha Brahmana 14.2.1.15

14.2.1.15

athāsyai stanamabhipadyate yaste stanaḥ śaśayo yo mayobhūriti yaste stano nihito guhāyāmityevaitadāha yo ratnadhā vasuvidyaḥ sudatra iti yo dhanānāṃ dātā vasuvitpaṇāvya ityevaitadāha yena viśvā puṣyasi vāryāṇīti yena sarvāndevāntsarvāṇi bhūtāni bibharṣītyevaitadāha sarasvati tamiha dhātave'kariti vāgvai sarasvatī saiṣā gharmadughā yajño vai vāgyajñamasmabhyam prayaca yena devānprīṇāmetyevaitadāhātha gārhapatyasyārdhamaityurvantarikṣamanvemītyasāveva bandhuḥ

He then touches her udder, with (Vâg. S. XXXVIII, 5; Rig-v. I, 164, 49), 'This ever-flowing, grateful udder of thine,'--that is to say, 'This udder of thine placed in secret;'--'treasure-giving, wealth-granting, bountiful,'--that is to say, 'which is a giver of treasures, a granter of wealth, and precious;'--'whereby thou furtherest all desirable things,'--that is to say, 'whereby thou supportest all the gods and all creatures;'--'O Sarasvatî, move that hither for us to suck,'--Sarasvatî, doubtless, is Speech, and so is this (cow) which yields the Gharma milk; and Speech is worship: thus he means to say, 'Grant us worship whereby we may please the gods.' He then steps up to the site of the Gârhapatya with, 'I pass along the wide aerial realm,'--the mystic import of this is the same as before.