It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "When the treasures of Persia and Rome are opened to you, what kind of people will you be?" Abdul Rahman bin Awf (may Allah be pleased with him) said: We will be as Allah has commanded. The Messenger of Allah (peace and blessings be upon him) said: "Or otherwise: you will compete with one another, then envy one another, then turn your backs on one another, and hate one another, or something like that. Then you will go to the dwellings of the Muhajirun and place some of them over the necks of others."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13729
Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) narrates: I heard the Messenger of Allah (peace and blessings be upon him) say: "Nuh (peace be upon him) fasted his whole life except for the days of Eid al-Fitr and Eid al-Adha; Dawud (peace be upon him) fasted half his life; and Ibrahim (peace be upon him) fasted three days of every month, (and in this way) he fasted his whole life and also broke his fast his whole life."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13730