Sunan Abu Dawood, Chapter: Purification (Kitab Al-Taharah)

Dawud ibn Salih ibn Dinar at-Tammar quoted his mother as saying that her mistress sent her with some pudding (harisah) to Aisha who was offering prayer. She made a sign to me to place it down. A cat came and ate some of it, but when Aisha finished her prayer, she ate from the place where the cat had eaten. She stated: The Messenger of Allah (peace_be_upon_him) said: It is not unclean: it is one of those who go round among you. She added: I saw the Messenger of Allah (peace_be_upon_him) performing ablution from the water left over by the cat.