Abū Bakr ibn in-Naḍr bin Abīn-Naḍr narrated to me, he said Abūn-Naḍr Hāshim bin ul-Qāsim narrated to me, Abū Aqīl, companion of Buhayyah, narrated to us, he said:
‘I was sitting near al-Qāsim bin Ubayd Allah and Yahyā bin Sa’īd [bin Qays al-Madanī al-Qāḍī], when Yahyā said to al-Qāsim: ‘Oh Abā Muhammad! Indeed it is gravely harmful for the likes of you to be asked about something from the affair of this Dīn, and then knowledge of it is not found with you, and no relief [in the form of an answer]’ -or- ‘…knowledge and no articulation’. So al-Qāsim said [to Yahyā bin Sa’īd]: ‘Where did that come from?’ [Yahyā] said: ‘It is because you are the son of two Imāms of guidance- a descendent of Abu Bakr and Umar.’ [al-Qāsim] said to him: ‘More harmful than that- according to whoever reflects about Allah- is to speak without knowledge or to take [Ḥadīth] from someone who is not trustworthy’. [Abū Aqīl] said: ‘So [Yahyā bin Sa’īd] was quiet and did not respond to him’.

وَحَدَّثَنِي أَبُو بَكْرِ بْنُ النَّضْرِ بْنِ أَبِي النَّضْرِ، قَالَ حَدَّثَنِي أَبُو النَّضْرِ، هَاشِمُ بْنُ الْقَاسِمِ حَدَّثَنَا أَبُو عَقِيلٍ، صَاحِبُ بُهَيَّةَ قَالَ كُنْتُ جَالِسًا عِنْدَ الْقَاسِمِ بْنِ عُبَيْدِ اللَّهِ وَيَحْيَى بْنِ سَعِيدٍ فَقَالَ يَحْيَى لِلْقَاسِمِ يَا أَبَا مُحَمَّدٍ إِنَّهُ قَبِيحٌ عَلَى مِثْلِكَ عَظِيمٌ أَنْ تُسْأَلَ عَنْ شَىْءٍ مِنْ أَمْرِ هَذَا الدِّينِ فَلاَ يُوجَدَ عِنْدَكَ مِنْهُ عِلْمٌ وَلاَ فَرَجٌ - أَوْ عِلْمٌ وَلاَ مَخْرَجٌ - فَقَالَ لَهُ الْقَاسِمُ وَعَمَّ ذَاكَ قَالَ لأَنَّكَ ابْنُ إِمَامَىْ هُدًى ابْنُ أَبِي بَكْرٍ وَعُمَرَ . قَالَ يَقُولُ لَهُ الْقَاسِمُ أَقْبَحُ مِنْ ذَاكَ عِنْدَ مَنْ عَقَلَ عَنِ اللَّهِ أَنْ أَقُولَ بِغَيْرِ عِلْمٍ أَوْ آخُذَ عَنْ غَيْرِ ثِقَةٍ . قَالَ فَسَكَتَ فَمَا أَجَابَهُ .