Śatapatha Brāhmaṇa ("of a hundred paths") 3.2.2.23

3.2.2.23

atha yatra suptvā | punarnāvadrāsyanbhavati tadvācayati punarmanaḥ punarāyurma āganpunaḥ prāṇaḥ punarātmā ma āganpunaścakṣuḥ punaḥ śrotram ma āganniti sarve ha vā ete svapato 'pakrāmanti prāṇa eva na tairevaitatsuptvā punaḥ saṃgacate tasmādāha punarmanaḥ punarāyurma āganpunaḥ prāṇaḥ punarātmā ma āganpunaścakṣuḥ punaḥ śrotram ma āgan vaiśvānaro adabdhastanūpā agnirnaḥ pātu duritādavadyāditi tadyadevātra svapnena vā yena vā mithyākarma tasmānnaḥ sarvasmādagnirgopāyatvityevaitadāha tasmādāha vaiśvānaro adabdhastanūpā agnirnaḥ pātu duritādavadyāditi

And when he has slept and does not wish to fall asleep again, (the Adhvaryu) makes him mutter the text (Vâg. S. IV, 15), 'Thought and life have come back to me, breath and soul have come back to me, eye and ear have come back to me;' for all these depart from him when he sleeps; the breath alone does not; and after he has slept he again unites with them: therefore he says, 'Thought and life have come back to me...'--'May Agni Vaisvânara, the unassailable preserver of lives, preserve us from mishap and shame!' whereby he means to say, 'May Agni save us from whatever mistake (may be committed) on this occasion, either by sleep or otherwise:' this is why he says, 'May Agni Vaisvânara, the unassailable preserver of lives, preserve us from mishap and shame!'