Śatapatha Brāhmaṇa ("of a hundred paths") 7.5.2.10

7.5.2.10

taddhaike 'pi | yadyekaḥ paśurbhavati pañcaiva kṛtvaḥ sapta-sapta pratyasyanti pañca vā etānpaśūnupadadhāti sapta-sapta vā ekaikasminpaśau prāṇāstadeṣu sarveṣu prāṇāndadhma iti na tathā kuryādetasminvai paśau sarveṣām paśūnāṃ rūpaṃ tadyadetasminpratyasyati tadevaiṣu sarveṣu prāṇāndadhāti

Now, even if there is only one victim, some people thrust five times seven (into that one head), thinking, 'Those five victims he puts down (symbolically), and there are seven vital airs in each victim: thus we put the vital airs into all of them.' Let him not do so, for in this animal the form of all animals is contained; and when he thrusts (seven chips) into this one, he thereby puts the vital airs into all of them.