Shiva Purana
पार्थिवं शिवलिंगं च विप्रो यदि न पूजयेत् । स याति नरकं घोरं शूलप्रोतं सुदारुणम् २६ ।
If a brahmin does not worship the earthen phallic image he shall fall in the terrible hell with a terrible trident pierced through his body.
english translation
pArthivaM zivaliMgaM ca vipro yadi na pUjayet । sa yAti narakaM ghoraM zUlaprotaM sudAruNam 26 ।
hk transliteration by Sanscript