Shiva Purana
एतदेव पदं प्राप्यं रुद्राराधनकांक्षिणाम् ॥ रुद्राणां तद्धि सालोक्यक्रमात्सायुज्यदम्मुने ॥ २०॥
This region is attainable by those who desire the propitiation of Rudras. O sage, it yields the Sāyujya of Rudras gradually through Sālokya.
english translation
etadeva padaM prApyaM rudrArAdhanakAMkSiNAm ॥ rudrANAM taddhi sAlokyakramAtsAyujyadammune ॥ 20॥
hk transliteration by Sanscript