Mishkat al-Masabih #1984

Anas said that the Prophet visited Umm Sulaim, and when she brought him some dates and clarified butter he said, “Put your butter back in its container and your dates in their vessel, for I am fasting.” He then went to a separate part of the house and prayed a prayer which was not one of the prescribed prayers, and invoked a blessing on Umm Sulaim and the inhabitants of her house. Bukhari transmitted it.