Sahih Bukhari Volume 3, Book 30, Hadith 1964

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، حَدَّثَنَا اللَّيْثُ، حَدَّثَنِي ابْنُ الْهَادِ، عَنْ عَبْدِ اللَّهِ بْنِ خَبَّابٍ، عَنْ أَبِي سَعِيدٍ ـ رضى الله عنه ـ أَنَّهُ سَمِعَ النَّبِيَّ صلى الله عليه وسلم يَقُولُ ‏"‏ لاَ تُوَاصِلُوا، فَأَيُّكُمْ إِذَا أَرَادَ أَنْ يُوَاصِلَ فَلْيُوَاصِلْ حَتَّى السَّحَرِ ‏"‏‏.‏ قَالُوا فَإِنَّكَ تُوَاصِلُ يَا رَسُولَ اللَّهِ‏.‏ قَالَ ‏"‏ إِنِّي لَسْتُ كَهَيْئَتِكُمْ، إِنِّي أَبِيتُ لِي مُطْعِمٌ يُطْعِمُنِي وَسَاقٍ يَسْقِينِ ‏"‏‏

Narrated By Abu Sa'id : That he had heard the Prophet saying, "Do not fast continuously (practise Al-Wisal), and if you intend to lengthen your fast, then carry it on only till the Suhur (before the following dawn)." The people said to him, "But you practice (Al-Wisal), O Allah's Apostle!" He replied, "I am not similar to you, for during my sleep I have One Who makes me eat and drink."