Agniveshyagrihyasutra 2.6.8.10

2.6.8.10

athāñjalinodakamādāyotthāyādityābhimukhastiṣṭan praṇavena vyāhṛtībhiḥ saha gāyatryābhimantrya trirūrdhvaṃ prakṣipet \

Then, having taken water in his joined palms, having stood up facing the sun, having consecrated it with the Gāyatrī together with the sacred syllable Om and the mystic utterances, he should cast it upward three times.