Shiva Purana
शिवानाममयं लिंगं नित्यं पूज्यं महर्षिभिः । यतश्च सर्वलिंगेषु तस्मात्पूज्यं विधानतः २७ ।
Since the phallic image is enjoined to be worshipped even by the sages, it shall be worshipped by every one in the manner stipulated.
english translation
zivAnAmamayaM liMgaM nityaM pUjyaM maharSibhiH । yatazca sarvaliMgeSu tasmAtpUjyaM vidhAnataH 27 ।
hk transliteration by Sanscript