Narrated AbuQatadah: Kabshah, daughter of Ka'b ibn Malik and wife of Ibn AbuQatadah, reported: AbuQatadah visited (me) and I poured out water for him for ablution. A cat came and drank some of it and he tilted the vessel for it until it drank some of it. Kabshah said: He saw me looking at him; he asked me: Are you surprised, my niece? I said: Yes. He then reported the Messenger of Allah (ﷺ) as saying: It is not unclean; it is one of those (males or females) who go round among you.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ الْقَعْنَبِيُّ، عَنْ مَالِكٍ، عَنْ إِسْحَاقَ بْنِ عَبْدِ اللَّهِ بْنِ أَبِي طَلْحَةَ، عَنْ حُمَيْدَةَ بِنْتِ عُبَيْدِ بْنِ رِفَاعَةَ، عَنْ كَبْشَةَ بِنْتِ كَعْبِ بْنِ مَالِكٍ، - وَكَانَتْ تَحْتَ ابْنِ أَبِي قَتَادَةَ - أَنَّ أَبَا قَتَادَةَ، دَخَلَ فَسَكَبَتْ لَهُ وَضُوءًا فَجَاءَتْ هِرَّةٌ فَشَرِبَتْ مِنْهُ فَأَصْغَى لَهَا الإِنَاءَ حَتَّى شَرِبَتْ قَالَتْ كَبْشَةُ فَرَآنِي أَنْظُرُ إِلَيْهِ فَقَالَ أَتَعْجَبِينَ يَا ابْنَةَ أَخِي فَقُلْتُ نَعَمْ . فَقَالَ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِنَّهَا لَيْسَتْ بِنَجَسٍ إِنَّهَا مِنَ الطَّوَّافِينَ عَلَيْكُمْ وَالطَّوَّافَاتِ " .
sunnah.com