Shatapatha Brahmana 13.1.8

Pragâpati poured forth the life-sap of the horse. When poured forth, it weighed down the rik (hymn-verse) and the sâman (hymn-tune). The Vaisvadeva (offerings) upheld that (Asvamedha): thus, when he offers the Vaisvadevas, it is for the upholding of the Asvamedha.

With (Vâg. S. XXII, 20), 'To Ka hail! To the Who hail! To the Whoever hail!' he makes the one relating to Pragâpati the first (or chief one), and thus upholds (the Asvamedha) by means of the deities with Pragâpati as their chief.

'Hail, meditation (we give) unto him meditated upon! Hail, the mind unto the Lord of creatures! Hail, thought unto him, the known!' what the mystic sense of the former (utterances) was that it is here.

'To Aditi hail! To Aditi, the mighty, hail! To Aditi, the most merciful, hail!' Aditi, doubtless, is this (earth): it is by her that he upholds it.

'To Sarasvatî hail! To Sarasvatî, the pure, hail! To Sarasvatî, the great, hail!' Sarasvatî, doubtless, is speech: by speech he thus upholds it.

'To Pûshan hail! To Pûshan, the protector of travellers, hail! To Pûshan, the watcher of men, hail!' Pûshan, doubtless, is cattle: by means of cattle he thus upholds it.

'To Tvashtri hail! To Tvashtri, the seminal, hail! To Tvashtri, the multiform hail!' Tvashtri, doubtless, is the fashioner of the couples of animals: by means of forms he thus upholds it.

'To Vishnu hail! To Vishnu, the protector of what grows, hail! To Vishnu, the bald, hail!' Vishnu, doubtless, is the sacrifice: by sacrifice he thus upholds it. With (Vâg. XXII, 21), 'Let every mortal espouse the friendship of the divine guide,...,' he offers last of all a full (-spoon)-oblation; for the full-offering is this (earth): he thus finally establishes himself on this (earth).