Sahih Muslim Book 006, Hadith Number 2430.

Chapter : It is forbidden to observe uninterrupted fasting.

Abu Huraira (Allah be pleased with him) reported Allah's Messenger (may peace be upon him) as saying: Abstain from Saum-Wisal. They (his Companions) said: Messenger of Allah, but you observe Saum Wisal. Upon this he said: You are not like me in this matter, for I spend my night (in a state) that my Lord feeds me and provides me drink Devote yourselves to the deeds (the burden of which) you can bear.

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