The Messenger of Allah ﷺ said to me, "Have I not been told that you stand in prayer all night and fast all day?"I replied, "I do that."He said, "If you keep doing this, your eyes will sink and your soul will grow weary. Your soul has a right over you, and your family has a right over you. So fast and break your fast, pray and sleep."
قال لي رسول الله ﷺ: ألم أخبر أنك تقوم الليل وتصوم النهار؟ قلت: إني أفعل ذلك. قال: فإنك إن فعلت ذلك هجمت عينك، ونفهت نفسك، وإن لنفسك حقا، ولأهلك حقا، فصم وأفطر، وقم ونم.
Bukhari narrated it in tahajjud (1153), and Muslim narrated it in fasting (1159/188), both from Sufyan, from Amr, from Abu Abbas, who said, I heard Abdullah bin Amr, and he mentioned it. Amr is Ibn Dinar. Abu Abbas is Saaib bin Faruq, known as the poet. His saying "hajamat" means "weakened due to excessive lack of sleep." His saying "nafihat" means "grew exhausted."This hadith has a long story, narrated by Imam Ahmad (6477) from Hushaym, from Husayn bin Abdul-Rahman and Mughira Dabbi, from Mujahid, from Abdullah bin Amr, who said, My father married me to a woman from Quraysh. When she came in to me, I found myself unable to pay her any attention, because of my devotion to worship, fasting, and prayer. So Amr bin As came to his daughter-in-law and went in to see her, and said to her, "How have you found your husband?" She said, "The best of men, or like the best of husbands, a man who has not looked into our private affairs nor known our bed." He turned to me, rebuked me and bit me with his tongue, saying, "I married you to a woman of Quraysh with noble lineage, and you have neglected her, and done this and that." Then he went to the Prophet ﷺ and complained about me. The Prophet ﷺ sent for me, and I came to him. He said to me, "Do you fast during the day?" I said, "Yes." He said, "And do you stand in prayer at night?" I said, "Yes." He said, "But I fast and break my fast, I pray and I sleep, and I touch women. Whoever turns away from my sunnah is not of me." He said, "Recite the Quran once every month." I said, "I find myself capable of more than that." He said, "Then recite it every ten days." I said, "I find myself capable of more than that." One of the two narrators, either Husayn or Mughira, said, He said, "Then recite it every three days." Then he said, "Fast three days out of every month." I said, "I am capable of more than that." He kept raising the amount for me until he said, "Fast one day and break your fast the next, for that is the best of fasting, and it is the fasting of my brother Dawud ﷺ."Husayn said in his narration, then he ﷺ said, "Every worshiper has a burst of enthusiasm, and every burst of enthusiasm is followed by a lull. Whoever's lull leads back to the sunnah has found guidance, but whoever's lull leads to something else has been ruined."Mujahid said, When Abdullah bin Amr grew weak and old, he would fast days like that, joining some to others so as to gain strength, then break his fast after those days. He said, He also used to recite his portion of the Quran in that way, sometimes adding to it and sometimes reducing it, but always completing the full amount, either in seven days or in three. He said, He would then say afterward, "That I had accepted the concession of the Messenger of Allah ﷺ would be dearer to me than what I did instead, but I departed from him over a matter that I dislike to now oppose by turning to something else."Its chain of transmission is sahih. Bukhari narrated it through the route of Mughira Dabbi in the virtues of the Quran (5052), though he abridged it.