Śatapatha Brāhmaṇa ("of a hundred paths") 3.3.3.8

3.3.3.8

athājāyām pratīcīnamukhyāṃ vācayati | tapasastanūrasīti tapaso ha vā eṣā prajāpateḥ sambhūtā yadajā tasmādāha tapasastanūrasīti prajāpatervarṇa iti sā yattriḥ saṃvatsarasya vijāyate tena prajāpatervarṇaḥ parameṇa paśunā krīyasa iti sā yattriḥ saṃvatsarasya vijāyate tena paramaḥ paśuḥ sahasrapoṣam puṣeyamityāśiṣamevaitadāśāste bhūmā vai sahasram bhūmānaṃ gacānītyevaitadāha

He then makes him (the sacrificer) say on the she-goat, which stands facing the west, 'Thou art the bodily form of fervour,'--that she-goat was indeed produced as the bodily form of fervour, of Pragâpati; hence he says, 'Thou art the bodily form of fervour,'--'Pragâpati's kind,' because she brings forth three times in the year, therefore she is Pragâpati's kind. 'Thou art bought with the most excellent animal,' because she brings forth three times in the year, she is the most excellent of animals. 'May I increase with a thousandfold increase!' Thereby he implores a blessing: a thousand meaning abundance, he thereby means to say, 'May I obtain abundance!'