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

AbuSufyan ibn Sa'id ibn al-Mughirah reported that he entered upon Umm Habibah who presented him a glass of sawiq (a drink prepared with flour and water) to drink. He called for water and rinsed his mouth. She said: O my cousin, don't you perform ablution? The Prophet (peace_be_upon_him) said: Perform ablution after eating anything cooked with fire, or he said: anything touched by fire.