Shiva Purana
मंत्रैरेकैकशस्तैस्तु विचिन्त्या दीप्तमूर्तयः ॥ त्रिगुणं त्रिगुणी कृत्य द्विजकन्याकृतं सितम् ॥ २२ ॥
They chanted mantras one by one and meditated on the glowing forms. Triple the white cotton made by the twin girls.
english translation
maMtrairekaikazastaistu vicintyA dIptamUrtayaH ॥ triguNaM triguNI kRtya dvijakanyAkRtaM sitam ॥ 22 ॥
hk transliteration by Sanscript