Shatapatha Brahmana 4.6.1.10

4.6.1.10

tadu hovāca yājñavalkyaḥ | abhyeva ṣuṇuyānna soma indramasuto mamāda nābrahmāṇo maghavānaṃ sutāsa ityṛṣiṇābhyanūktaṃ na vā anyasyai kasyai cana devatāyai sakṛdabhiṣuṇoti tadanyathā tataḥ karoti yatho cānyābhyo devatābhyastasmādabhyeva ṣuṇuyāditi

As to this Yâgñavalkya said, 'Nay, let him press: "The unpressed Soma delighted not the mighty Indra, nor the outpressed draughts without prayer," thus spake the Rishi (Rig-veda VII, 26, I). For no other deity does he strike but once: thus he does different from what he does for other deities,--therefore let him press!'