Śatapatha Brāhmaṇa ("of a hundred paths") 13.5.2.10

13.5.2.10

apa vā etebhya āyurdevatāḥ krāmanti ye yajñepūtām vā cam vadanti vācamevaitatpunate devayajyāyai devatānāmanapakramāya yā ca gomṛge vapā bhavati yā cājetūpare te aśve pratyavadhāyāharanti nāśvasya vapāstīti vadanto na tathā kuryādaśvasyaiva pratyakṣam meda āharetprajñātā itarāḥ

For, indeed, life and the deities depart from those who at the sacrifice speak impure speech: it is their speech they thereby purify so that the deities may not depart from the divine service. Now (some) put the omentum of the Gomriga and that of the hornless he-goat upon the horse and then take it (to the Âhavanîya), saying, 'The horse has no omentum.' Let him not do so: of the horse he should certainly take the fat; the (omenta of the) others are normal.