Shiva Purana
स्वयमेव कृतद्वारं रुद्रा क्षं स्यादिहोत्तमम् । यत्तु पौरुषयत्नेन कृतं तन्मध्यमं भवेत् २३ ।
That which has a natural hole from end to end is the most excellent; that which is bored through by human effort is the middling one.
english translation
svayameva kRtadvAraM rudrA kSaM syAdihottamam । yattu pauruSayatnena kRtaM tanmadhyamaM bhavet 23 ।
hk transliteration by Sanscript