Śatapatha Brāhmaṇa ("of a hundred paths") 1.3.3.7

1.3.3.7

atha barhi stṛṇāti | ayaṃ vai stupaḥ prastaro 'tha yānyavāñci lomāni tānyevāsya yaditaram barhistānyevāsminnetaddadhāti tasmādbarhi stṛṇāti

He now spreads the barhis (on the altar). For the prastara is the top-knot; and this other sacrificial grass is for this (sacrifice) what other hair there is below that (top-knot, viz. the beard, &c.):--that (hair) he thereby puts on it, and for this reason he spreads the barhis.