Shiva Purana
पूजां कृत्वाथ तल्लिंगं शिरसा धारयेत्सदा । विभूतिस्त्रिविधा प्रोक्ता लोकवेदशिवाग्निभिः ५७ ।
They shall keep the liṅga after worship on their head for ever. The ash is of three types, derived from ordinary fire, Vedic fire and Śiva fire.
english translation
pUjAM kRtvAtha talliMgaM zirasA dhArayetsadA । vibhUtistrividhA proktA lokavedazivAgnibhiH 57 ।
hk transliteration by Sanscript