Shiva Purana
तेनोमिति जगत्कृत्स्नं कुरुते प्रथमं शिवः ॥ शिवो हि प्रणवो ह्येष प्रणवो हि शिवः स्मृतः ॥ ४३ ॥
By this process Lord Śiva first creates the entire universe. This is the oṁkāra of Lord Śiva and the oṁkāra is called Śiva.
english translation
tenomiti jagatkRtsnaM kurute prathamaM zivaH ॥ zivo hi praNavo hyeSa praNavo hi zivaH smRtaH ॥ 43 ॥
hk transliteration by Sanscript