It was narrated that 'Aishah said: "The Messenger of Allah came to me one day and said: 'Do you have anything (to eat)?' I said: 'No.' he said: 'Then I am fasting.' Then he came to me after that day, and I had been given some Hais. I had kept some for him as he liked Hais. She said: 'O Messenger of Allah, we have been given some Hais and I kept some for you.' He said: 'Bring it here. I started the day fasting.' Then he ate some of it, then he said: 'The likeness of a voluntary fast is that of a man who allocated some of his wealth to give in charity; if he wishes he may go ahead and give it, and if he wishes he may keep it."'