Shatapatha Brahmana 4.1.1.6

4.1.1.6

devā ha vai yajñaṃ tanvānāḥ | te 'surarakṣasebhya āsaṅgādbibhayāṃ cakruste hocuḥ saṃsthāpayāma yajñaṃ yadi no 'surarakṣakānyāsajeyuḥ saṃsthita eva no yajñaḥ syāditi

Now, once on a time, the gods, while performing sacrifice, were afraid of an attack from the Asura-Rakshas. They said, 'Let us completely establish the sacrifice: if the Asura-Rakshas should then attack us, our sacrifice will at least be completely established.'