Shiva Purana
नैवाशौचं प्रपद्येत तत्पुत्रादिविशेषतः ॥ शिवचारार्थमथवा शिवविद्यार्थमेव वा ॥ खनेद्वा भुवि तद्देहं दहेद्वा शुचिनाग्निना ॥ ५८ ॥
One should not become unclean, especially his sons and other relatives. Or to walk around Lord Śiva or to learn about Lord Śiva. He may dig his body in the ground or burn it with pure fire.
english translation
naivAzaucaM prapadyeta tatputrAdivizeSataH ॥ zivacArArthamathavA zivavidyArthameva vA ॥ khanedvA bhuvi taddehaM dahedvA zucinAgninA ॥ 58 ॥
hk transliteration by Sanscript