Śatapatha Brāhmaṇa ("of a hundred paths") 3.9.4.17

3.9.4.17

atha prahariṣyan | yaṃ dviṣyāttam manasā dhyāyedamuṣmā aham praharāmi na tubhyamiti yo nvevemam mānuṣam brāhmaṇaṃ hanti taṃ nveva paricakṣate 'tha kiṃ ya etaṃ devī hi somo ghnanti vā enametadyadabhiṣuṇvanti tametena ghnanti tathāta udeti tathā saṃjīvati tathānenasyam bhavati yadyu na dviṣyādapi tṛṇameva manasā dhyāyettatho anenasyam bhavati

Being about to beat (the Soma with the pressing-stone), let him think in his mind of him he hates: 'Herewith I strike N.N., not thee!' Now whosoever kills a human Brâhman here, he, forsooth, is deemed guilty,--how much more so he who strikes him (Soma), for Soma is a god. But they do kill him when they press him;--they kill him with that (stone): thus he rises from thence, thus he lives; and thus no guilt is incurred.. But if he hate no one, he may even think of a straw, and thus no guilt is incurred.