Śatapatha Brāhmaṇa ("of a hundred paths") 1.8.2.4

1.8.2.4

tāṃ hotānumantrayate | eṣā te agne samittayā vardhasva cā ca pyāyasva vardhiṣīmahi ca vayamā ca pyāsiṣīmahīti tadyathaivādaḥ samidhyamānāyānvāhaivamevaitadanvāha tadetaddhotuḥ karma sa yadi manyeta na hotā vedetyapi svayameva yajamāno 'numantrayeta

The Hotri consecrates it (the kindling-stick), with the formula (Vâg. S. II, 14 a), 'This, O Agni, is thy kindler; mayest thou grow and increase by it; and may we also grow and increase!' for even as before he recited over the fire when it was being kindled, so also now he recites. This is the Hotri's duty; but the sacrificer himself may pronounce the consecratory formula, if he think that the Hotri does not know it.