Śatapatha Brāhmaṇa ("of a hundred paths") 4.3.3.6

4.3.3.6

tadyanmarutvatīyāngṛhṇāti | etadvā indrasya niṣkevalyaṃ savanaṃ yanmādhyandinaṃ savanaṃ tena vṛtramajighāsattena vyajigīṣata maruto vā ityaśvatthe 'pakramya tasthuḥ kṣatraṃ vā indro viśo maruto viśā vai kṣatriyo balavānbhavati tasmādāśvatthe ṛtupātre syātāṃ kārṣmaryamaye tveva bhavataḥ

Then as to why he draws the Marutvatîya cups. Now this, the midday pressing feast, is Indra's special (nishkevalya) feast: thereby he strove to smite Vritra, thereby he strove to vanquish him. But the Maruts, having on that account withdrawn, were standing on an Asvattha tree (Ficus Religiosa). Now Indra is the nobility, and the Maruts are the people, and through the people the noble becomes strong: therefore the two Ritu cups (they say) may be of asvattha wood; but in reality they are of kârshmarya wood.