Sahih Muslim Book - 0, Hadith - 33

و حَدَّثَنِي 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 شَيْءٍ مِنْ أَمْرِ هَذَا الدِّينِ فَلَا يُوجَدَ عِنْدَكَ مِنْهُ عِلْمٌ وَلَا فَرَجٌ أَوْ عِلْمٌ وَلَا مَخْرَجٌ فَقَالَ لَهُ الْقَاسِمُ وَعَمَّ ذَاكَ قَالَ لِأَنَّكَ ابْنُ إِمَامَيْ هُدًى ابْنُ أَبِي بَكْرٍ وَعُمَرَ قَالَ يَقُولُ لَهُ الْقَاسِمُ أَقْبَحُ مِنْ ذَاكَ عِنْدَ مَنْ عَقَلَ عَنْ اللَّهِ أَنْ أَقُولَ بِغَيْرِ عِلْمٍ أَوْ آخُذَ عَنْ غَيْرِ ثِقَةٍ قَالَ فَسَكَتَ فَمَا أَجَابَهُ.

It was narrated that Abu 'Aqil, the companion of Buhayyah said: "I was sitting with Al-Qasim bin 'Ubaidullah and Yahya bin Sa'eed. Yahya said to Al-Qasim: 'O Abu Muhammad! How grave it is for a great man like you to be asked a question about this religion and you have no knowledge of it and no answer.' Al-Qasim said to him: 'Why is that?' He said: 'Because you are the son of two Imam of guidance, the son of Abu Bakr and 'Umar.' Al-Qasim said to him: 'What is worse than that is one who knows about Allah but speaks without knowledge, or accepts a report from one who is not trustworthy.' He fell silent and did not answer him."