Shiva Purana
उदङ्मुखः प्राङ्मुखो वा मौनी चैकाग्रमानसः ॥ विशोध्य पञ्चतत्त्वानि दहनप्लावनादिभिः ॥ २१ ॥
He should face north or east and remain silent with a single mind Purify the five elements by burning, floating and so on.
english translation
udaGmukhaH prAGmukho vA maunI caikAgramAnasaH ॥ vizodhya paJcatattvAni dahanaplAvanAdibhiH ॥ 21 ॥
hk transliteration by Sanscript