Śatapatha Brāhmaṇa ("of a hundred paths") 1.5.4.3

1.5.4.3

atheḍo yajati | prajā ghā iḍo yadā vai retaḥ siktaṃ prajāyate 'tha tadīḍitamivānnamicamānaṃ carati tatpraivaitajjanayati tasmādiḍo yajati

He then pronounces the offering-prayer to the Ids. The Ids, doubtless, are offspring; when the seed thus cast springs into life, then it moves about in quest of food, as it were, praising (îd). Hence he thereby makes him (the sacrificer) propagate offspring: this is the reason why he, pronounces the prayer to the Ids.