Śatapatha Brāhmaṇa ("of a hundred paths") 5.2.3.9

5.2.3.9

athāgrayaṇeṣṭyā yajate | sarvānvā eṣa yajñakratūnavarunddhe sarvā iṣṭīrapi darvihomānyo rājasūyena yajate devasṛṣṭo vā eṣeṣṭiryadāgrayaṇeṣṭiranayā me pīṣṭamasadanayāpi sūyā iti tasmādāgrayaṇeṣṭyā yajata oṣadhīrvā eṣa sūyamāno 'bhi sūyate tadoṣadhīrevaitadanamīvā akilviṣāḥ kurute 'namīvā akilviṣā oṣadhīrabhi sūyā iti tasya gaurdakṣiṇā

Thereupon he performs the offering of first-fruits; for verily he who performs the Râgasûya secures for himself (the benefits of) all sacrificial rites, all ishtis, even the spoon-offerings; and instituted by the gods, in truth, is that ishti, the Âgrayaneshti: 'May this also be offered by me! May I be consecrated by this (offering) also!' thus he thinks, and therefore he performs the offering of first-fruits. Moreover, it is for the plants that he who is consecrated, is consecrated; therefore he now makes the plants healthy and faultless, thinking, 'May I be consecrated for (the obtainment of) healthy, faultless plants (crops)!' A cow is the fee for this (offering).