Shiva Purana

siva.sh/siva-purana/saturda-samhita/11/41

जगत्त्रयीसर्जनार्थं शंकरं नीललोहितम् ।। ललाटेऽचिन्तयत्सोयन्तपस्युग्रे च संस्थितः ।। ४१ ।।

sanskrit

Remaining in a severe penance, he contemplated on Śiva, the blue-necked, in his forehead for the creation of the three worlds.

english translation

jagattrayIsarjanArthaM zaMkaraM nIlalohitam || lalATe'cintayatsoyantapasyugre ca saMsthitaH || 41 ||

hk transliteration by Sanscript