´Hamzah bin 'Abdullah bin 'Umar narrated that his father said:` "Hafsah, the wife of the Prophet said: 'There is no fast for the one who does not intend (to fast) before dawn."'
Hadith ReferenceSunan an-Nasa'i / The Book of Fasting / Hadith: 2338
Hadith Gradingالألبانی:صحيح موقوف | زبیر علی زئی:إسناده صحيح