Narrated Ibn 'Abbas:

that regarding "Alif Lam Mim. The Romans have been defeated" (In the nearest land, and they, after their defeat, will be victorious. Within Bid' years...) (30 1 & 2)" The Messenger of Allah ﷺ said to Abu Bakr about the wager: "Why were you not more cautious Abu Bakr? For indeed Al-Bid' refers to what is from three to nine."

حَدَّثَنَا أَبُو مُوسَى، مُحَمَّدُ بْنُ الْمُثَنَّى حَدَّثَنَا مُحَمَّدُ بْنُ خَالِدِ بْنِ عَثْمَةَ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ عَبْدِ الرَّحْمَنِ الْجُمَحِيُّ، حَدَّثَنَا ابْنُ شِهَابٍ الزُّهْرِيُّ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ بْنِ عُتْبَةَ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لأَبِي بَكْرٍ فِي مُنَاحَبَةٍ : ( الم* غُلِبَتِ الرُّومُ ) " أَلاَّ احْتَطْتَ يَا أَبَا بَكْرٍ فَإِنَّ الْبِضْعَ مَا بَيْنَ الثَّلاَثِ إِلَى التِّسْعِ " .

قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ غَرِيبٌ مِنْ حَدِيثِ الزُّهْرِيِّ عَنْ عُبَيْدِ اللَّهِ عَنِ ابْنِ عَبَّاسٍ .