Hadith 1764
Abu Hurairah and 'Aishah (May Allah be pleased with them) said:
عن أبي هريرة وعائشة رضي الله عنهما أن النبي صلى الله عليه وسلم نهى عن الوصال. ((متفق عليه)).
The Prophet (ﷺ) prohibited observing continuous voluntary fasts beyond one day. [Al-Bukhari and Muslim].
In plain words
The Prophet forbade joining voluntary fasts together without breaking them, going beyond a single day. It is a mercy that spares the body and favours steady worship.
Reference : Riyad as-Salihin 1764 In-book reference : Book 17, Hadith 254