سنن النسائي

It was narrated from 'Aishah, the mother of the Believers, that the Prophet (ﷺ) used to come to her when he was fasting and say: "Do you have anything this morning that you can give me to eat?" we would say no, and he would say: "I am fasting." Then after that he came and she said: "I have been given a gift." He said: "What is it?" she said: "Hais." He said: "I started the day fasting," but then he ate.