Śatapatha Brāhmaṇa ("of a hundred paths") 1.5.4.5

1.5.4.5

atha svāhāsvāheti yajati | hemanto vā ṛtūnāṃ svāhākāro hemanto hīmāḥ prajāḥ svaṃ vaśamupanayate tasmāddhemanmlāyantyoṣadhayaḥ pra vanaspatīnām palāśāni mucyante pratitirāmiva vayāṃsi bhavantyadhastarāmiva vayāṃsi patanti vipatitalomeva pāpaḥ puruṣo bhavati hemanto hīmāḥ prajāḥ svaṃ vaśamupanayate svāha vai tamardhaṃ kurute śriye 'nnādyāya yasminnardhe bhavati ya evametadveda

He then pronounces the offering-prayer with 'Svâhâ! Svâhâ!' The Svâhâ-call, indeed, is what the winter is among the seasons; for the winter subjects these creatures to its will: hence in winter the plants wither, and the leaves fall off the trees; the birds retire more and more, and fly lower and lower; and the wicked man has his hair, as it were, falling off; for the winter subjects these creatures to its will. And, verily, he who knows this, makes that locality wherein he lives, his own, for his own happiness and supply of food.