Śatapatha Brāhmaṇa ("of a hundred paths") 1.6.3.7

1.6.3.7

indro ha vā īkṣāṃ cakre | idaṃ vai mā somādantaryantīti sa yathā balīyānabalīyasa evamanupahūta eva yo droṇakalaśe śukra āsa tam bhakṣayāṃ cakāra sa hainaṃ jihiṃsa so 'sya viṣvaṅṅeva prāṇebhyo dudrāva mukhāddhaivāsya na dudrāvātha sarvebhyo 'nyebhyaḥ prāṇebhyo 'dravattadadaḥ sautrāmaṇītīṣṭistasyāṃ tadvyākhyāyate yathainaṃ devā abhiṣajyan

Indra thought with himself, 'They are now excluding me from Soma!' and though uninvited, he consumed what pure (Soma) there was in the tub, even as the stronger (consumes) that of a weaker. That (Soma) however, injured him; it flowed in all directions from (the openings of) his vital airs; from his mouth alone it did not flow, but from all the other (openings of the) vital airs it flowed; hence (was instituted) at that time the ishti, called Sautrâmanî: on the occasion of that (ceremony) it is explained how the gods healed him.