Śatapatha Brāhmaṇa ("of a hundred paths") 1.4.1.37

1.4.1.37

taddhaike | purastāddhāyye dadhatyannaṃ dhāyye mukhata idamannādyaṃ dadhma iti vadantastadu tathā na kuryādanavakLptātasyaiṣā bhavati yaḥ purastāddhāyye dadhāti daśamī vāhi tarhyekādaśī vā sampadyate tasyo haivaiṣāvakLptā bhavati yasyaitāmaṣṭamīmanvāhustasmādupariṣṭādeva dhāyye dadhyāt

Here now some people place the two (dhâyyâs) additional kindling verses before (the eighth sâmidhenî), arguing, 'The two dhâyyâs mean food: this edible food we place in front (or, in the mouth, mukhatah).' But let him not do this: for with him who inserts the additional verses before (the eighth), the latter (the eighth) is clearly out of its place, since in that case it (and the succeeding verse) become the tenth and eleventh verses. With him, on the other hand, for whom they recite this as the eighth (kindling verse), it is indeed in its proper place: let him therefore insert the two additional verses after (the ninth).