The Messenger of Allah ﷺ forbade continuous fasting without breaking it between days.
حدثنا عبد الجبار بن محمد قال حدثنا بقية عن محمد بن زياد الألهاني سمع عبد الله بن أبي قيس يقول سمعت
نهى رسول الله ﷺ عن الوصال في الصيام
No references are available.
Its isnad is sahih, though there is discussion regarding Baqiya bin Walid and his use of "an" (indicating a possibly concealed break in transmission). As for Muhammad bin Ziyad Alhani, he is trustworthy, and his hadith is found in the collections of the group, except Muslim. The hadith has already appeared at 24467.