Śatapatha Brāhmaṇa ("of a hundred paths") 13.1.3.5

13.1.3.5

yathā vai haviṣo'hutasya skandet evametatpaśo skandati yam prokṣitamanālabdhamutsṛjanti yadrūpāṇi juhoti sarvahutamevainaṃ juhotyaskandāyāskannaṃ hi tadyaddhutasya skandati hiṅkārāya svāhā hiṅkṛtāya svāhetyetāni vā aśvasya rūpāṇi tānyevāvarunddhe

And even as some of the offering-material may be spilled before it is offered, so also (part) of the victim is here spilled in that they let loose the sprinkled (horse) before it is slaughtered. When he offers (the oblations relating to) the Forms (rûpa), he offers that (horse) as one that is wholly offered, so as to make good any spilling; for unspilled is what is spilled of the offered (material). With (Vâg. S. XXII, 7-8),'To the Hiṅ-call, hail! to the (horse) consecrated by Hiṅ, hail!...' (he offers them); for these are the forms (qualities) of the horse: it is them he now obtains.