The Messenger of Allah ﷺ... My father said, and Rawh narrated to us, Shuba narrated to us, I heard Habib bin Abu Thabit say, I heard Abu al-Abbas the poet, who was truthful, narrating from Abdullah bin Amr, who said, the Messenger of Allah ﷺ said, "Abdullah bin Amr, you fast continuously. If you fast every day and stand in prayer every night, your eyes will sink and your soul will grow weary. There is no fasting for one who fasts forever. Fast three days of each month, and that will count as fasting the entire year."I said, "I am able to do more than that."He said, "Then fast the fast of Dawud. He used to fast one day and break his fast the next, and he never fled when he met the enemy."Rawh said, "his soul will be exhausted."
حدثنا محمد بن جعفر حدثنا شعبة عن حبيب عن أبي العباس
أن رسول الله ﷺ قال أبي وحدثنا روح حدثنا شعبة سمعت حبيب بن أبي ثابت سمعت أبا العباس الشاعر وكان صدوقا يحدث عن عبد الله بن عمرو قال قال رسول الله ﷺ يا عبد الله بن عمرو إنك تصوم الدهر فإذا صمت الدهر وقمت الليل هجمت له العين ونفهت له النفس لا صام من صام الأبد صم ثلاثة أيام من الشهر صوم الدهر كله قال قلت إني أطيق قال صم صوم داود فإنه كان يصوم يوما ويفطر يوما ولا يفر إذا لاقى وقال روح نهثت له النفس
Its isnad is sahih. It is part of the long hadith that has already passed at 6477, where we noted it. Part of its meaning has already passed at 6534. See also 6761, 6762, 6764, and part of its meaning will come at 6789, 6843, 6874. Tayalisi related it at 2255 in this manner, from Shubah, with this same isnad. See also Bukhari 3:32, 4:195, and 6:327, Muslim 1:320, Nasai 1:326, and Ibn Saad 4/2/9.As for his saying "the eye sank in" (hajamat lahu al-ayn), Ibn Athir said, meaning it sank and receded into its place, and from this comes the word "hujum" applied to a people, meaning entering upon them.As for his saying "nafihat" with the noon vowelled with fatha and the fa with kasra, Hafiz said in 3:32, meaning it grew weary. Ismaili related that Abu Yaala transmitted it as "tafihat," with a ta in place of the noon, and he considered this weak. Here in H it occurs with a ta as well. This may be a copyist's or printer's error.