Sahih Bukhari
Fasting
Volume: 003 / Book Number: 031 / Hadith Number: 188
Narrated 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."