Shiva Purana
शिवदीक्षान्वितो भक्तो महाप्रसादसंज्ञकम् । सर्वेषामपि लिंगानां नैवेद्यं भक्षयेच्छुभम् ११ ।
A devotee who has received the initiation (Shiva Diksha) and is blessed with great grace should not consume the offerings (naivedya) or food of any Shiva Linga unless it is pure and auspicious.
english translation
zivadIkSAnvito bhakto mahAprasAdasaMjJakam । sarveSAmapi liMgAnAM naivedyaM bhakSayecchubham 11 ।
hk transliteration by Sanscript