Musnad Ahmad 32:1100

Marwan ibn Mu'awiyah narrated to us, he said: Hilal ibn Suwayd Abu Mu'alla informed me, he said: I heard Anas ibn Malik saying: Three birds were gifted to the Messenger of Allah, may Allah bless him and grant him peace, so he fed one bird to his servant. When the next day came, she brought it to him. The Messenger of Allah, may Allah bless him and grant him peace, said to her: "Did I not forbid you from keeping anything for tomorrow? For Allah brings the provision of every tomorrow."