Riyad as-Saliheen 1764
Abu Hurairah and 'Aishah (May Allah be pleased with them) said:
The Prophet ﷺ prohibited observing continuous voluntary fasts beyond one day.
[Al-Bukhari and Muslim].
عن أبي هريرة وعائشة رضي الله عنهما أن النبي ﷺ نهى عن الوصال. ((متفق عليه)).
Classification
Sahih (Authentic)
References
Riyad as-Saliheen 1764
Riyad as-Saliheen Book of Prohibited actions, Hadith 254