Shatapatha Brahmana 1.1.3.12

1.1.3.12

atha yajñapātrāṇi prokṣati | daivyāya karmaṇo śundhadhvaṃ devayajyāyā iti daivyāya hi karmaṇo śundhati devayajyāyai yadvo 'śuddhaḥ parājaghnuridaṃ vastacundhāmīti tadyadevaiṣāmatrāśuddhastakṣā vānyo vāmedhyaḥ kaścitparāhanti tadevaiṣāmetadadbhirmedhyaṃ karoti tasmādāha yadvo 'śuddhāḥ parājaghnuridaṃ vastacundhāmīti

He then sprinkles the sacrificial vessels, with the text (Vâg. S. I, 13 g), 'Be ye pure for the divine work, for the sacrifice to the gods!' for it is for the divine work, the sacrifice to the gods, that he consecrates them. 'Whatever, that belongs to you, the impure have defiled by touching, that I hereby purify for you!' For whatever belonging to them some impure one--either a carpenter or some other impure person--has on this occasion desecrated by touching, that he thereby renders sacrificially pure for them by means of the water; and therefore he says, 'Whatever, that belongs to you, the impure have defiled by touching, that I hereby purify for you!'