Shiva Purana
रुद्राग्निर्यत्परं वीर्यन्तद्भस्म परिकीर्तितम् ॥ तस्मात्सर्वेषु कालेषु वीर्यवान्भस्मसंयुतः ॥ ९१ ॥
The gícat virility of the Rudra fire is what is glorified as the ashes. Hence a person possessing the ashes is a virile and powerful person at all times.
english translation
rudrAgniryatparaM vIryantadbhasma parikIrtitam ॥ tasmAtsarveSu kAleSu vIryavAnbhasmasaMyutaH ॥ 91 ॥
hk transliteration by Sanscript