Shiva Purana

siva.sh/siva-purana/saturda-samhita/8/2

भैरवः पूर्णरूपो हि शंकरस्य परात्मनः ।। मूढास्तं वै न जानन्ति मोहिताश्शिवमायया ।। २ ।।

sanskrit

Bhairava is the prior form of Siva, the great soul. Fools who are deluded by Śiva’s Māyā do not know about it.

english translation

bhairavaH pUrNarUpo hi zaMkarasya parAtmanaH || mUDhAstaM vai na jAnanti mohitAzzivamAyayA || 2 ||

hk transliteration by Sanscript