Śatapatha Brāhmaṇa ("of a hundred paths") 5.2.4.20

5.2.4.20

athāpratīkṣam punarāyanti | sa haitenāpi pratisaraṃ kurvīta sa yasyāṃ tato diśi bhavati tatpratītya juhoti pratīcīnaphalo vā apāmārgaḥ sa yo hāsmai tatra kiṃcitkaroti tameva tatpratyagdhūrvati tasya nāmādiśedabadhiṣmāmumasau hata iti tannāṣṭrā rakṣāṃsi hanti

Thereupon they return (to the sacrificial ground) without looking back. Now by this (ceremony) also he may make for himself a counter-charm. In whatever direction from there (his evil-wisher) is, looking back thither he offers; for the Apâmârga is of a backward effect: whosoever does anything to him there, him indeed he thereby pitches backward. Let him indicate the name of that one, saying, 'We have slain so and so! So and so is slain!' thus he slays the fiends, the Rakshas.