"Three to nine." (1)

This is a ḥasan gharīb ḥadīth (2) from this chain, from the narration of al-Zuhrī, from ʿUbayd Allāh, from Ibn ʿAbbās.

3471 — Muḥammad ibn Ismāʿīl narrated to us, saying: Ismāʿīl ibn Abī Uways narrated to us, saying: Ibn Abī al-Zinād narrated to me, from Abū al-Zinād, from ʿUrwah ibn al-Zubayr, from Niyār ibn Mukram al-Aslamī, who said:

When the verse was revealed: {Alif Lām Mīm (1) The Romans have been defeated (2) in the nearest land, and they, after their defeat, will be victorious (3) within a few years} — on the day this verse was revealed, Persia was victorious over the Romans. The Muslims wished for the Romans to prevail over them, because both they and the Romans were People of the Book. Concerning this, Allah the Exalted said: {And on that day the believers will rejoice (4) in the victory of Allah. He grants victory to whom He wills, and He is the Mighty, the Merciful.} But the Quraysh wished for Persia to prevail, because both they and the Persians were not People of the Book and did not believe in the Resurrection. When Allah the Exalted revealed this verse, Abū Bakr al-Ṣiddīq went out proclaiming throughout the streets of Mecca: {Alif Lām Mīm (1) The Romans have been defeated (2) in the nearest land, and they, after their defeat, will be victorious (3) within a few years} —

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(1) ʿAbd Allāh ibn ʿAbd al-Raḥmān al-Jumaḥī — three narrators reported from him; Ibn Ḥibbān mentioned him in "al-Thiqāt," and al-Tirmidhī deemed this ḥadīth of his ḥasan. The rest of his narrators are trustworthy. It was also recorded by al-Ṭaḥāwī in "Sharḥ al-Mushkil" (2990). Al-Munāḥabah means wagering and betting.
(2) In (S): "A gharīb ḥadīth."