Shiva Purana

siva.sh/siva-purana/uma-samhita/5/31

अधीत्य यो द्विजो वेदं ब्रह्मज्ञानं शिवात्मकम् ।। यदि त्यजति यो मूढः सुरापानस्य तत्समम् ।। ३१ ।।

sanskrit

If a brahmin learns the Vedas and acquires knowledge of Brahman and Śiva, but eschews it later on he commits a sin equal to that of drinking wine.

english translation

adhItya yo dvijo vedaM brahmajJAnaM zivAtmakam || yadi tyajati yo mUDhaH surApAnasya tatsamam || 31 ||

hk transliteration by Sanscript