It is narrated from Sayyiduna al-Mustawrid (may Allah be pleased with him) that he said to Sayyiduna Amr bin al-As (may Allah be pleased with him): "Will the Hour be established while the Romans are the most numerous of people?" Sayyiduna Amr (may Allah be pleased with him) said: "Think carefully about what you are saying!" He replied: "I am only telling you what I heard from the Messenger of Allah (peace and blessings be upon him)." Then Sayyiduna Amr bin al-As (may Allah be pleased with him) said: "If you say that, (then it may well be true), for they have four qualities: they are the quickest of people to turn back and attack after retreating; they are the best of people towards the poor, the needy and the weak; they are the most forbearing of people at a time of tribulation; and the fourth quality is very good and fine: they are the foremost of people in resisting the oppression of kings."
Imam al-Tabarani (may Allah have mercy on him) said: "This hadith is narrated from Sayyiduna al-Mustawrid (may Allah be pleased with him) only with this chain; Musa bin Ulayy (may Allah have mercy on him) is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب الميم / 8668
Hadith Takhrij«أخرجه مسلم فى «صحيحه» برقم: 2898، وأحمد فى «مسنده» برقم: 18307، والبزار فى «مسنده» برقم: 3463، والطبراني فى «الكبير» برقم: 718، 719، 736، 737، والطبراني فى «الأوسط» برقم: 206، 2677»