´It was narrated that 'Aishah said:` "The Messenger of Allah used to fast until we said: 'He does not want to break his fast.' And he used not to fast until we said: 'He does not want to fast."'
Hadith ReferenceSunan an-Nasa'i / The Book of Fasting / Hadith: 2349
Hadith Gradingالألبانی:صحيح الإسناد | زبیر علی زئی:إسناده حسن