Skandapurana 5.161.20

5.161.20

.. brāhmaṇā ūcuḥ .. ..
yadyevaṃ vada viprāsya puraścaraṇasaṃjñitām ..
saptamīmadya vipreṃdra varākasya viśuddhaye .. 6.162.20 ..

The brahmins said:
“If it is so, tell him now, O vipra, best of brahmins, of that seventh lunar day
named Puraścaraṇa, for the purification of that wretched man.”