Shiva Purana
भस्मनिष्ठस्य नश्यन्ति देषा भस्माग्निसंगमात् ॥ भस्मस्नानविशुद्धात्मा भस्मनिष्ठ इति स्मृतः ॥ ९२ ॥
A person who has bathed with the ashes is called Bhasmaniṣṭha. His faults perish due to the contact of Bhasma fire.
english translation
bhasmaniSThasya nazyanti deSA bhasmAgnisaMgamAt ॥ bhasmasnAnavizuddhAtmA bhasmaniSTha iti smRtaH ॥ 92 ॥
hk transliteration by Sanscript