Śatapatha Brāhmaṇa ("of a hundred paths") 2.4.1.8

2.4.1.8

sa āhavanīyamupatiṣṭhate | āganma viśvavedasamasmabhyaṃ vasuvittamam agne samrāḍabhi dyumnamabhi saha āyacasvetyathopaviśya tṛṇānyapalumpati

He approaches the Âhavanîya fire, with the text (Vâg. S. III, 38 seq.), 'We have approached (thee), the all-knowing, the most liberal dispenser of goods: O Agni, sovereign lord, bestow on us lustre and strength!' Having then sat down he sweeps the blades of grass (into the fire).