Anandakanda 1.15.8

1.15.8

māsārdhamāsaṃ deveśi tasmāttailaṃ samāharet /
śuddhadeho virekādyairarcitāgnigurudvijaḥ //

For a month or half a month, O ruler of the gods; from that one should take out the oil.
Having one's body purified by purgation and the like, having worshiped the fire, the guru, and the twice-born,