(35) باب صِيَامِ الْمُتَطَوِّعِ بِغَيْرِ تَبْيِيتٍ
Aishah, the Mother of the Believers, narrated:
"The Messenger of Allah visited me one day and said: 'Do you have anything (to eat)?'" She said: "I said: 'No.' He said: 'Then I am fasting.'"
Reference: Jami` at-Tirmidhi 733
In-book reference: Book 8, Hadith 52
English translation: Vol. 2, Book 3, Hadith 733