Muwatta Malik, Book 54, Hadith 1796 (In-Book)

Malik related to me from Nafi from Abu Lubaba that the Messenger of Allah, may Allah bless him and grant him peace, forbade killing snakes which were in the houses.

حَدَّثَنِي مَالِكٌ، عَنْ نَافِعٍ، عَنْ أَبِي لُبَابَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنْ قَتْلِ الْحَيَّاتِ الَّتِي فِي الْبُيُوتِ ‏.‏

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also referenced under: Book 54, Hadith 31 (USC-MSA)