Śatapatha Brāhmaṇa ("of a hundred paths") 1.2.4.7

1.2.4.7

vāyurasi tigmatejā iti | etadvai tejiṣṭhaṃ tejo yadayaṃ yo 'yam pavata eṣa hīmāṃllokāṃstiryaṅṅanupavate saṃśyatyevainametaddviṣato badha iti yadi nābhicaredyadyu abhicaredamuṣya badha iti brūyāttena saṃśitena nātmānamupaspṛśati na pṛthivīṃ nedanena vajreṇa saṃśitenātmānaṃ vā pṛthivīṃ vā hinasānīti tasmānnātmānamupaspṛśati na pṛthivīm

'The sharp-edged Vâyu (wind) art thou!' he adds; for that indeed is the sharpest edge, to wit, that (wind) which here blows: for that one sweeps right across these worlds. He thereby makes it sharp. When he (further) says: 'The killer of the enemy!' let him, whether he wishes to exorcise or not, say: 'The killer of so and so!' When it has been sharpened, he must not touch either himself or the earth with it: 'Lest I should hurt either myself or the earth with that sharp thunderbolt,' thus he thinks, and for that reason he does not touch either himself or the earth with it.