Sahih Bukhari Volume 003, Book 031, Hadith Number 188.
Narated By Abu Said Al-Khudri : Allah's Apostle said, "Do not fast continuously day and night (practise Al-Wisal) and if anyone of you intends to fast continuously day and night, he should continue till the Suhur time." They said, "But you practise Al-Wisal, O Allah's Apostle!" The Prophet said, "I am not similar to you;. during my sleep I have One Who makes me eat and drink."