Kaṭha Āraṇyaka 2.21

2.21

yatprāvṛñjata tasmātpravargyāṇi tasmātpravargyas . tasmādyassapravargyeṇa yajñena yajate mukhyo brahmavarcasī bhavati . eṣa vāva tarhi yajña āsīdyadeṣa jyoti-ṣṭomas . tadyathā vā idamagnerjātādagnayo'nye vihriyanta evamasmādanye yajña-kratavaḥ prajāyante . tasmāj jyotiṣṭome pravṛñjyādyajñasyordhvatvāya . nokthye pravṛñjyāt . prajā vai paśava ukthāni . yadukthye pravṛñjyātprajāñcāsya paśūṃśca nirdahet . tasmātprajākāmāya paśukāmāya na pravṛñjyād . asau vā ādityo rudro mahāvīro . rudrā deva prajāmpaśūnparivṛṇakti . tasmādvāsasā patnīmpra-śchādayati prajāyā apradāhāya . sarvatopakrame pravṛñjyād 207 bhūrbhuvassvar 208 namo vāce namo vācaspataya iti . vāgvai sarasvatī . yā vāguditā yā cānuditā tasyai vāce nama iti 208-1 --- nama ṛṣibhyo mantrakṛdbhyo mantravidbhya iti 208-2 --- mā māmṛṣayo mantrakṛto mantravidaḥ parāduriti 208-3 --- daivīṃ vācamudyāsamiti daivīmeva vācaṃ vadati 208-4 śivāmajasrāmiti śivāmevaināmajasrāṃ karoti 209 juṣṭāṃ devebhya iti devebhya evaināṃ juṣṭāṃ karoti 210 svadhāvatīmpitṛbhya iti pitṛbhya evaināṃ svadhāvatīṅ karoti 211 śuśrūṣeṇyāṃ manuṣyebhya iti . manuṣyebhya evaināṃ śuśrūṣeṇyāṅ karoti 212 tammā devā avantu śobhāyai pitaro'numadantv ityanv enaṃ devā avanti śobhāyai pitaro'numadanti 213 sucakṣā ahamakṣibhyāṃ suvarcā mukhena suśrutkarṇābhyāṃ bhūyāsamiti yathāyajur . apavarge'pi mārjayante 214 śivā naśśantamā bhava sumṛḻīkā sarasvatīti . vāgvai sarasvatī .

Because they performed the Pravargya, therefore they are Pravargyas, therefore it is the Pravargya. Therefore he who sacrifices with a sacrifice accompanied by the Pravargya becomes prominent and endowed with priestly splendor. That indeed was the sacrifice then, which is this Jyotiṣṭoma. Just as indeed other fires are carried out from this produced fire, so other sacrifice-rituals are produced from this. Therefore he should perform the Pravargya in the Jyotiṣṭoma for the elevation of the sacrifice. He should not perform the Pravargya in the Ukthya. Offspring and cattle, indeed, are the ukthas. If he should perform the Pravargya in the Ukthya, he would burn up his offspring and cattle. Therefore he should not perform the Pravargya for one who desires offspring or for one who desires cattle. Yonder sun indeed is Rudra, the Mahāvīra. Rudra surely excludes offspring and cattle. Therefore he covers the wife with a cloth to prevent burning of offspring. He should perform the Pravargya at the commencement of everything. 'Bhūr bhuvas svar.' 'Homage to speech, homage to the lord of speech.' Sarasvatī, indeed, is speech. 'Whichever speech is uttered and whichever is unuttered, to that speech be homage.' [...] 'Homage to the ṛṣis, makers of mantras, knowers of mantras.' [...] 'May the ṛṣis, makers of mantras, knowers of mantras, not abandon me.' [...] 'May I speak divine speech,' thus he speaks only divine speech. 'Auspicious, unexhausted,' thus he makes it auspicious and unexhausted. 'Pleasing to the gods,' thus he makes it pleasing to the gods. 'Accompanied by the svadhā call for the ancestors,' thus he makes it accompanied by the svadhā call for the ancestors. 'Worthy of being heard by men,' thus he makes it worthy of being heard by men. 'May the gods aid me for beauty, may the ancestors approve,' saying this the gods aid him, the ancestors approve him for beauty. 'May I be good of sight with my eyes, of good splendor with my face, good of hearing with my ears,' as according to the yajus. At the completion also they cleanse themselves: 'Be auspicious, most beneficent, very gracious to us, O Sarasvatī.' Sarasvatī, indeed, is speech.