Shiva Purana

siva.sh/siva-purana/rudra-samhita/91/21

यद्यपूतम्भवेद्भस्म चितायाश्च त्वयोदितम् ।। नित्यमस्यांगगं देवैश्शिरोभिर्द्धार्यते कथम्।।२१।।

sanskrit

If, as you say, the ash from the funeral pyre is unholy, how is it that the same transferred to Śiva’s body is taken thence and worn on the head by the gods?

english translation

yadyapUtambhavedbhasma citAyAzca tvayoditam || nityamasyAMgagaM devaizzirobhirddhAryate katham||21||

hk transliteration by Sanscript