Sahih Muslim Book 6, Hadith Number 2426.

Chapter : It is forbidden to observe uninterrupted fasting.

Ibn ‘Umar (Allah be pleased with both of them) said that the Apostle of Allah (may peace be upon him) forbade uninterrupted fasting. They (some of the Companions) said: You yourself fast uninterruptedly, whereupon he said: I am not like you. I am fed and supplied drink (by Allah).