Śatapatha Brāhmaṇa ("of a hundred paths") 4.6.8.7

4.6.8.7

rājānam praṇayati | udyata evaiṣa āgnīdhrīyo 'gnirbhavatyathaita ekaikamevolmukamādāya yathādhiṣṇyaṃ viparāyanti taireva teṣāmulmukaiḥ praghnantīti sa smāha yājñavalkyo ye tathā kurvantītyetannvekamayanam

He leads forward the king (Soma). That Âgnîdhrîya fire has just been taken up on the support, when they take one fire-brand each (from the fire at the hall-door) and disperse to their several dhishnya hearths: 'They who do so,' said Yâgñavalkya, 'slay with those fire-brands of theirs.' This now is one way.