Śatapatha Brāhmaṇa ("of a hundred paths") 9.2.3.40

9.2.3.40

athaudumbarīmādadhāti | ūrgvai rasa udumbara ūrjaivainamedrasena prīṇāti karṇakavatī bhavati paśavo vai karṇakāḥ paśubhirevainametadannena prīṇāti yadi karṇakavatīṃ na vindeddadhidrapsamupahatyādadhyāttadyaddadhidrapsa upatiṣṭhate tadeva paśurūpam preddho agne dīdihi puro na iti virājādadhānyannaṃ virāḍannevainametatprīṇāti tisraḥ samidha ādadhāti trivṛdagniryāvānagniryāvatyasya mātrā tāvataivainametadannena prīṇāti

He then puts on one of udumbara (ficus glomerata) wood;--the Udumbara means strength and sap: with strength and sap he thus gratifies him. It has forking branches,--forking branches mean cattle: with cattle, as food, he thus gratifies him. If he cannot get one with bifurcate branches, let him take up a globule of sour curds and put it on (the wood): that globule of sour curds which supervenes is a form of cattle. With the virâg (verse, Vâg. S. XVII, 76; Rig-veda VII, I, 3), 'Kindled, blaze forth, O Agni, before us, (with inexhaustible flame, O youngest! perpetual viands accrue unto thee!)'--he puts it on;--the Virâg means food: with food he thus gratifies him. Three pieces of wood he puts on,--threefold is Agni: as great as Agni is, as great as is his measure, with so much food he thus gratifies him.