Hadithcore
Riyad as-Salihin, 1764

Abu Hurairah and 'Aishah (May Allah be pleased with them) said:

The Prophet (ﷺ) prohibited observing continuous voluntary fasts beyond one day. <b>[Al-Bukhari and Muslim]</b>.

عن أبي هريرة وعائشة رضي الله عنهما أن النبي صلى الله عليه وسلم نهى عن الوصال‏.‏ ‏(‏‏(‏متفق عليه‏)‏‏)‏‏.‏

References1 variant
In-Book Reference
Book 17, Hadith 254
Sharh · explanationclick to expand
<b>Guidance from the Hadiths:</b><br> 1) It is prohibited to fast uninterruptedly lest one should get bored with uninterrupted worship.<br> 2) They point out Allah’s vast mercy and kindness towards His servants. Indeed, He is more merciful to them than their own selves.