Shatapatha Brahmana 6.3.1.8

6.3.1.8

sruvaścātra srukca prajujyete | vāgvai srukprāṇaḥ sruvo vācā ca vai prāṇena caitadagre devāḥ karmānvaicaṃstasmātsruvaśca srukca

Both an offering-spoon (sruk) and a dipping-spoon (sruva) are used thereat; for the offering-spoon is speech, and the dipping-spoon is breath; and with speech and breath the gods sought this sacred rite at the beginning: hence there are an offering-spoon and a dipping-spoon.