Musnad Ahmad 25:637

Mu'awiyah ibn 'Amr narrated to us, Abu Ishaq narrated to us, from Sufyan, from Habib ibn Abi 'Amrah, from Sa'id ibn Jubayr, from Ibn 'Abbas, regarding His saying: {Alif-Lam-Mim. The Romans have been defeated} [Ar-Rum: 2]. He said: They were defeated and they defeated. He said: The polytheists used to love for Persia to prevail over the Romans, because they were people of idols. And the Muslims used to love for the Romans to prevail over Persia, because they were people of the Book. So they mentioned it to Abu Bakr, and Abu Bakr mentioned it to the Messenger of Allah (peace and blessings of Allah be upon him). The Messenger of Allah (peace and blessings of Allah be upon him) said: "As for them, they will surely prevail." He said: So Abu Bakr mentioned it to them, and they said: "Set a time limit between us and you. If we prevail, we shall have such and such, and if you prevail, you shall have such and such." So he set a time limit of five years, but they did not prevail. Abu Bakr mentioned that to the Prophet (peace and blessings of Allah be upon him), and he said: "Why did you not make it less?" He said: I think he said: "The ten?" - Sa'id ibn Jubayr said: The *bid'* (a few) is what is less than ten. Then the Romans prevailed afterwards. He said: That is His saying: {Alif-Lam-Mim. The Romans have been defeated} [Ar-Rum: 1] up to His saying: {And on that day the believers will rejoice} [Ar-Rum: 4]. He said: They will rejoice {with the victory of Allah} [Ar-Rum: 5].