Shiva Purana
एतानि खलु सर्वाणि कर्माणि मुनिसत्तम ॥ सुमहत्पातकान्याहुश्शिवनिन्दासमानि च ॥ २२ ॥
O best of sages these are indeed all the actions They say that these are very serious sins and are equal to blasphemy against Lord Śiva.
english translation
etAni khalu sarvANi karmANi munisattama ॥ sumahatpAtakAnyAhuzzivanindAsamAni ca ॥ 22 ॥
hk transliteration by Sanscript