Śatapatha Brāhmaṇa ("of a hundred paths") 4.5.4.14

4.5.4.14

tānu haika uttare tryahe gṛhṇanti | tadu tathā na kuryātpūrva evaināṃstryahe gṛhṇīyādyadyuttare tryahe grahīṣyantsyātpūrva evaināṃstryahe gṛhītvāthottare tryahe gṛhṇīyādevameva yathāpūrvaṃ viśvajiti sarvapṛṣṭha ekāha eva gṛhyante

Some, however, draw them on the last three days; but let him not do so: let him rather draw them on the first three days. But should he intend to draw them on the last three days, let him first draw them on the first three days and let him then draw them on the last three days. In like manner they are drawn (all three) in their proper order, on one and the same day, at the Visvagit with all the Prishthas.