Shiva Purana
सृष्टेः पूर्वं शिवः प्रोक्तः सृष्टेर्मध्ये शिवस्तथा॥ सृष्टेरन्ते शिवः प्रोक्तस्सर्वशून्ये तदा शिवः ॥ २०॥
Śiva is said to be before creation. Śiva is there in the midst of creation. Śiva is said to be at the end of creation. When everything is a void, Sadāśiva exists.
english translation
sRSTeH pUrvaM zivaH proktaH sRSTermadhye zivastathA॥ sRSTerante zivaH proktassarvazUnye tadA zivaH ॥ 20॥
hk transliteration by Sanscript