Shatapatha Brahmana 1.9.1.21

1.9.1.21

tadu haika āhuḥ | ubhe ca meti tathā hotāśiṣa ātmānaṃ nāntaretīti tadu tathā na brūyādyajamānasya vai yajña āśīḥ kiṃ nu tatrartvijāṃ yāṃ vai kāṃ ca yajña ṛtvija āśiṣamāśāsate yajamānasyaiva sā na ha sa etāṃ kva canāśiṣam pratiṣṭhāpayati ya āhobhe ca meti tasmādu brūyādubhe cainamityeva

Here now some say, 'And may both heaven and earth guard me (mâ)...,' arguing that in this way the Hotri does not exclude himself from the benediction. Let him not, however, say this; for, surely, the benediction at the sacrifice is for the sacrificer: what then have the officiating priests to do with it? Whatever blessing the officiating priests invoke at the sacrifice, that is for the sacrificer only. On the other hand, whoever says, 'and may both heaven and earth guard me...,' does not establish that blessing anywhere: let him therefore say, 'and may both heaven and earth guard this one....'