Śatapatha Brāhmaṇa ("of a hundred paths") 1.4.5.2

1.4.5.2

aṅghraṇā viṣṇo mā tvāvakramiṣamiti | yajño vai viṣṇustasmā evaitannihnute mā tvāvakramiṣamiti vasumatīmagne te cāyāmupastheṣamiti sādhvīmagne te cāyāmupastheṣamityevaitadāha

And again, 'May I not sin against thee with my foot, O Vishnu!' Vishnu, indeed, is the sacrifice: it is the latter therefore that he propitiates by saying, 'may I not sin against thee!' Further, 'May I step into thy wealth-abounding shade, O Agni!' whereby he says, 'may I step into thy auspicious shade, O Agni!'