Shiva Purana
तस्य वीर्यप्रभावश्च साकांक्षैस्त्रिदशैरपि ॥ न हि वर्णयितुं शक्यः स्वरूपं ज्ञातुमेव वा ॥ १९ ॥
The power of his virility cannot be adequately described even by the ambitious gods nor can his form be known.
english translation
tasya vIryaprabhAvazca sAkAMkSaistridazairapi ॥ na hi varNayituM zakyaH svarUpaM jJAtumeva vA ॥ 19 ॥
hk transliteration by Sanscript