Śatapatha Brāhmaṇa ("of a hundred paths") 3.9.3.32

3.9.3.32

sa yadyagniṣṭomaḥ syāt | yadi pracaraṇyāṃ saṃsravaḥ pariśiṣṭo 'laṃ homāya syāttaṃ juhuyādyadyu nālaṃ homāya syādaparaṃ caturgṛhītamājyaṃ gṛhītvā juhoti yamagne pṛtsu martyamavā vājeṣu yaṃ junāḥ sa yantā śaśvatīriṣaḥ svāhetyāgneyyā juhotyagnirvā agniṣṭomastadagnāvagniṣṭomam pratiṣṭhāpayati martavatyā puruṣasammito vā agniṣṭoma evaṃ juhuyādyadyagniṣṭomaḥ syāt

And if it be an Agnishtoma, and there be left a residue (of ghee poured together) in the prakaranî spoon sufficient for an oblation, let him offer that. But if it be not sufficient for an oblation, he takes another portion of ghee in four ladlings and offers it, with (Vâg. S. VI, 29; Rig-veda I, 27, 7), 'Whatever mortal thou favourest in battles, whomsoever thou speedest in the race, he winneth unfailing strength, Hail!' He offers with (a prayer) to Agni, because the Agnishtoma ('Agni's praise') means Agni; thus he establishes the Agnishtoma in Agni. [He offers] with (a verse) containing the word 'mortal,' because the Agnishtoma is of the same measure as man. Let hire then offer in this manner, if it be an Agnishtoma.