Language:
كتاب الصوم
30  
Fasting
(49)
Chapter: The punishment for the person who practises Al-Wisal very often.
(49)
باب التَّنْكِيلِ لِمَنْ أَكْثَرَ الْوِصَالَ
Sahih al-Bukhari 1966

Narrated Abu Huraira:

The Prophet (ﷺ) said twice, "(O you people) Be cautious! Do not practice Al-Wisal." The people said to him, "But you practice Al-Wisal?" The Prophet (ﷺ) replied, "My Lord gives me food and drink during my sleep. Do that much of deeds which is within your ability."

حَدَّثَنَا يَحْيَى، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، عَنْ مَعْمَرٍ، عَنْ هَمَّامٍ، أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ ـ رضى الله عنه ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏"‏ إِيَّاكُمْ وَالْوِصَالَ ‏"‏‏.‏ مَرَّتَيْنِ قِيلَ إِنَّكَ تُوَاصِلُ‏.‏ قَالَ ‏"‏ إِنِّي أَبِيتُ يُطْعِمُنِي رَبِّي وَيَسْقِينِ، فَاكْلَفُوا مِنَ الْعَمَلِ مَا تُطِيقُونَ ‏"‏‏.‏
Reference : Sahih al-Bukhari 1966
In-book reference : Book 30, Hadith 73
USC-MSA web (English) reference : Vol. 3, Book 31, Hadith 187
  (deprecated numbering scheme)