The Messenger of Allah ﷺ said, "Beware of continuous fasting. This is what I know."They said, "But you yourself fast continuously."He replied, "I am not like any of you. I spend the night with my Lord feeding me and giving me drink."
حدثنا عبد الرحمن عن مالك عن أبي الزناد عن الأعرج
قال رسول الله ﷺ إياكم والوصال كذاك علمي قالوا إنك تواصل قال إني لست كأحدكم إني أبيت يطعمني ربي ويسقيني
Its isnad is sahih, and it is in Muwatta, page 301. Muslim related it 1:304, through Mughira, who is Ibn Abdul-Rahman Hazami, from Abu Zinad, with this same isnad, similarly, at greater length. Bukhari also related it at greater length, 4:179-181, through Abdul-Razzaq from Mamar from Hammam from Abu Hurairah. The longer narration has already passed at 7162, related by Ammar from Abu Zura from Abu Hurairah.As for his statement in the middle of the hadith, "that is my knowledge," it appears that this is from the wording of Abdul-Rahman bin Mahdi, because what is in Muwatta is, "Beware of consecutive fasting, beware of consecutive fasting." Perhaps Ibn Mahdi heard it from Malik once, without repetition, and heard the narration from someone else, from Malik, with the repetition. So he clarified that what he knew of the narration from Malik was this version, without repetition.