(48) باب الْوِصَالِ، وَمَنْ قَالَ لَيْسَ فِي اللَّيْلِ صِيَامٌ
'Narrated Abu Sa`id:
That he had heard the Prophet (ﷺ) saying, "Do not fast continuously (practice 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 Messenger (ﷺ)!" He replied, "I am not similar to you, for during my sleep I have One Who makes me eat and drink."
Reference: Sahih al-Bukhari 1963
In-book reference: Book 30, Hadith 70
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 3, Book 31, Hadith 184