Shatapatha Brahmana 9.5.2.1

9.5.2.1

indra etattsarptaccamapaṣyat nyūnasyāptyā atiriktyai vyṛddhasya samṛddhyā atha ha vā īśvaro 'gniṃ citvā kiṃciddauritamāpattorvi vā hvalitoryadvā yadā ha vā etacyāparṇaḥ sāyakāyanaḥ śuśrāvātha haitatkarmopadadharṣa

Indra saw this seven-versed (hymn, suitable) for making good what is deficient, for reducing what is redundant, and for perfecting what is imperfect. And, indeed, after building the fire-altar, one is (still) apt to get into trouble, or to stumble, or what not. Now, when Syâparna Sâyakâyana heard this, he ventured upon this performance.