Śatapatha Brāhmaṇa ("of a hundred paths") 2.1.4.27

2.1.4.27

sa yattūṣṇīmupaspṛśati | tadasyām pratiṣṭhāyām pratiṣṭhanti so 'syām pratiṣṭhita ādhatte tathā na vyathate tadu haitatpaśceva dadhrira āsuriḥ pāñcirmādhukiḥ sarvaṃ vā anyadiyasitamiva prathamenaivodyatyādadhyādbhūrbhuvaḥ svariti tadevāniyasitamityato yatamathā kāmayeta tathā kuryāt

Now, when he touches it silently he thereby takes a firm footing on this resting-place; and having obtained a firm footing on it, he lays down (the fire): and thus he wavers not. Here now Âsuri, Pâñki, and Mâdhuki held it (the fire) slightly to the back (or west of the fire-place). 'For,' they argued, 'everything else (that is on the hearth) becomes, as it were, relaxed (on being touched by the fire): he should therefore, after holding it up, lay it down at the first (touching) with "Earth! ether! heaven!" for thus no relaxation takes place.' Let him then do this in whichever way he may deem proper.