وَحَدَّثَنِي بِشْرُ بْنُ الْحَكَمِ الْعَبْدِيُّ، قَالَ: سَمِعْتُ سُفْيَانَ بْنَ عُيَيْنَةَ يَقُولُ: أَخْبَرُونِي عَنْ أَبِي عَقِيلٍ صَاحِبِ بُهَيَّةَ أَنَّ ابْنًا لِعَبْدِ اللَّهِ بْنِ عُمَرَ سَأَلُوهُ عَنْ شَيْءٍ لَمْ يَكُنْ عِنْدَهُ فِيهِ عِلْمٌ، فَقَالَ لَهُ يَحْيَى بْنُ سَعِيدٍ: وَاللَّهِ إِنِّي لَأُعْظِمُ أَنْ يَكُونَ مِثْلُكَ وَأَنْتَ ابْنُ إِمَامَيِ الْهُدَى، يَعْنِي عُمَرَ وَابْنَ عُمَرَ، تُسْأَلُ عَنْ أَمْرٍ لَيْسَ عِنْدَكَ فِيهِ عِلْمٌ. فَقَالَ: أَعْظَمُ مِنْ ذَلِكَ وَاللَّهِ عِنْدَ اللَّهِ وَعِنْدَ مَنْ عَقَلَ عَنِ اللَّهِ أَنْ أَقُولَ بِغَيْرِ عِلْمٍ أَوْ أُخْبِرَ عَنْ غَيْرِ ثِقَةٍ. قَالَ: وَشَهِدَهُمَا أَبُو عَقِيلٍ يَحْيَى بْنُ الْمُتَوَكِّلِ حِينَ قَالَا ذَلِكَ.
Translation: Bishr ibn al-Ḥakam al-ʿAbdī narrated to me: “I heard Sufyān ibn ʿUyaynah say, ‘I was informed, on the authority of Abū ʿAqīl, the associate of Buhayyah, that people asked a son of ʿAbd Allāh ibn ʿUmar about something of which he had no knowledge. Yaḥyā ibn Saʿīd said to him: By God, I consider it a grave matter that someone like you, descended from two imams of guidance—meaning ʿUmar and Ibn ʿUmar—should be asked about something of which you have no knowledge. He replied: More grave than that, by God, in the sight of God and in the judgment of one who understands what is due to God, is that I speak without knowledge or report from an untrustworthy person.’” He said: Abū ʿAqīl, Yaḥyā ibn al-Mutawakkil, witnessed the two of them when they said this.
The first account names Abū Bakr and ʿUmar, while the second names ʿUmar and Ibn ʿUmar. Al-Nawawī resolves the apparent contradiction genealogically: al-Qāsim is al-Qāsim ibn ʿUbayd Allāh ibn ʿAbd Allāh ibn ʿUmar ibn al-Khaṭṭāb. His mother was Umm ʿAbd Allāh bint al-Qāsim ibn Muḥammad ibn Abī Bakr al-Ṣiddīq. Thus Abū Bakr is his senior ancestor through his mother; ʿUmar is his senior ancestor through his father; and Ibn ʿUmar is his actual paternal grandfather. The two descriptions are reconcilable, but neither original report should be rewritten to match the other.