Kauṣītaki (Śāṅkhāyana) Brāhmaṇa 26.2.3_3

26.2.3_3

atha ha sma āha paiṅgyo na ānantaryāt prayogaḥ syād atirikto vā eṣa mantraḥ syād yo avacanād dvir ucyate / (soma: chandomāh)

Then Paiṅgya said: “The performance should not proceed from the immediate continuation; for that mantra would be redundant which without prescription is spoken twice.”