Sunan Abi Dawud, Hadith 2353

Narrated Ibn 'Umar: The Messenger of Allah prohibited perpetual fasting. They (the people) said: You keep perpetual fasting, Messenger of Allah. He said: My position is not like that you yours. I am provided with food and drink.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ الْقَعْنَبِيُّ، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ نَهَى عَنِ الْوِصَالِ، قَالُوا فَإِنَّكَ تُوَاصِلُ يَا رَسُولَ اللَّهِ ‏.‏ قَالَ ‏ "‏ إِنِّي لَسْتُ كَهَيْئَتِكُمْ إِنِّي أُطْعَمُ وَأُسْقَى ‏" ‏ ‏.‏

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also referenced under: Hadith 2360 (DarusSalam)