Shatapatha Brahmana 1.9.2.17

1.9.2.17

athāgnīdāhānuprahareti | tūṣṇīmevānuprahṛtya cakṣuṣpā agne 'si cakṣurme pāhītyātmānamupaspṛśāte tano apyātmānaṃ nānupravṛṇakti

The Âgnîdhra then says, 'Throw (it) after!' [The Adhvaryu] having thrown it silently after (the prastara into the fire), touches himself, with the text (Vâg. S. II, 16 f), 'Guardian of the eye art thou, O Agni, guard mine eye!' and in this way he avoids throwing himself after (the prastara into the fire).