Sahih al-Bukhari, Volume 4, Book 56, Hadith 821 (USC-MSA) ⓘ
Narrated Sa`id bin Jubair: About Ibn `Abbas: `Umar bin Al-Khattab used to treat Ibn `Abbas very favorably `Abdur Rahman bin `Auf said to him. "We also have sons that are equal to him (but you are partial to him.)" `Umar said, "It is because of his knowledge." Then `Umar asked Ibn `Abbas about the interpretation of the Verse:- 'When come the Help of Allah and the conquest (of Mecca) (110.1) Ibn `Abbas said. "It portended the death of Allah's Messenger, which Allah had informed him of." `Umar said, "I do not know from this Verse but what you know."
حَدَّثَنَا مُحَمَّدُ بْنُ عَرْعَرَةَ، حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي بِشْرٍ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ كَانَ عُمَرُ بْنُ الْخَطَّابِ ـ رضى الله عنه ـ يُدْنِي ابْنَ عَبَّاسٍ، فَقَالَ لَهُ عَبْدُ الرَّحْمَنِ بْنُ عَوْفٍ إِنَّ لَنَا أَبْنَاءً مِثْلَهُ. فَقَالَ إِنَّهُ مِنْ حَيْثُ تَعْلَمُ. فَسَأَلَ عُمَرُ ابْنَ عَبَّاسٍ عَنْ هَذِهِ الآيَةِ {إِذَا جَاءَ نَصْرُ اللَّهِ وَالْفَتْحُ}. فَقَالَ أَجَلُ رَسُولِ اللَّهِ صلى الله عليه وسلم أَعْلَمَهُ إِيَّاهُ. قَالَ مَا أَعْلَمُ مِنْهَا إِلاَّ مَا تَعْلَمُ.
also referenced under: Book 61, Hadith 131 (In-Book) & Hadith 3627 (DarusSalam)