Shiva Purana
तथा संकरजातीनां नाध्वशुद्धिर्विधीयते ॥ तैप्यकृत्रिमभावश्चेच्छिवे परमकारणे ॥ ६४ ॥
Similarly, the purification of the road is not prescribed for hybrids. If there is no artificial feeling, then Lord Śiva is the supreme cause.
english translation
tathA saMkarajAtInAM nAdhvazuddhirvidhIyate ॥ taipyakRtrimabhAvazcecchive paramakAraNe ॥ 64 ॥
hk transliteration by Sanscript