Shiva Purana
अथान्यायार्जितैश्चापि भक्त्या चेच्छिवमर्चयेत् ॥ न तस्य प्रत्यवायो ऽस्ति भाववश्यो यतः प्रभुः ॥ ४८ ॥
Then one should worship Lord Śiva with devotion, even if he has earned it by righteous means. There is no countermeasure to that because the Lord is subject to emotion.
english translation
athAnyAyArjitaizcApi bhaktyA cecchivamarcayet ॥ na tasya pratyavAyo 'sti bhAvavazyo yataH prabhuH ॥ 48 ॥
hk transliteration by Sanscript