Verse 13.4.1.15

tasyai saptadaśa sāmidhenyo bhavanti saptadaśo vai prajāpatiḥ prajāpatiraśvamedho'śvamedhasyaivāptyai vṛdhanvantāvājyabhāgau yajamānasyaiva vṛddhyai pūṣaṃstava vrate vayam pathaspathaḥ paripatiṃ vacasyetyupāṃśu haviṣo yājyānuvākye vratavatyanyā bhavati pathanvatyanyā vīryaṃ vai vrataṃ vīryasyāptyai vīryasyāvaruddhyā atha yatpathanvatyaśvāyaivaitatsvastyayanaṃ karotyanuṣṭubhau saṃyājye vāgvā anuṣṭubvāgvai prajāpatiḥ prajāpatiraśvamedho'śvamedhasyaivāptyai vāsaḥśataṃ dakṣiṇā rūpaṃ vā etatpuruṣasya yadvāsastasmādyameva kaṃ ca suvāsasamāhuḥ ko nvayamiti rūpasamṛddho hi bhavati rūpeṇaivainaṃ samardhayati śatam bhavati śatāyurvai puruṣaḥ śatendriya āyurevendriyaṃ vīryamātmandhatte

Preview of English translation:

15. For this (offering) there are seventeen kindling-verses, for the obtainment of the Ashvamedha, for Prajapati is seventeenfold, and the Ashvamedha is Prajapati. The two butter-portions are possessed of 'growth,' even for the growth of the Sacrificer. [The verses, Vajasaneyi Samhita XXXIV, 41, 42,] “Pushan, in thy sway we [shall never suffer harm, we (who) here are singers of thy praises],” and 'The hymn (?) lovingly composed by desire of praise hath reached the guardian of every path: (may he, Pushan, grant unto us draughts of light (?), and fulfil our every prayer!'), pronounced in a low voice, are the anuvakya and yajya of the chief oblation. The one contains (the word) “sway,” the other (the word) “path”; for sway is vigour: (thus it is) in order to his gaining and securing vigour; and as to why (the other) contains (the word) “path,” he thereby secures successful progress to the horse. The invitatory and offering formulas of the Svishtakrit are two anushtubh verses; for the Anushtubh is speech, and Prajapati is speech, and the Ashvamedha is Prajapati: thus it is for the obtainment of the Ashvamedha. The priests’ fee consists of a hundred garments, for that—to wit, the garment—is man’s outward appearance, whence people (on seeing) Any well-clad man, ask, 'Who can this be? for he is perfect in his outward appearance: with outward appearance he thus endows him. There are a hundred of them, for man has a life of a hundred (years), and a hundred energies: life, and energy, vigour, he thus gains for himself.

For a detailled translation, including proper diacritics and footnotes, go the full English translation.