The Book Pertaining to Repentance and Exhortation to Repentance (Kitab Al-Tauba)
Muslim :: Book 37 : Hadith 6639
Abu Huraira reported Allah's Messenger (may peace be upon him) as saying that a servant transgressed the litnit in committing sins. The rest of the hadith is the same but there is no mention of the story of the cat in it and in the hadith transmitted on the authority of Ziibaidl (the words are):" Allah, the Exalted and Glorious, said to everything which had taken a part of lies ashes to return what it had taken."