Shaqiq al-Balkhi reported: It was said to Ibn al-Mubarak, may Allah have mercy on him, “When you pray, why do you not sit with us afterwards?” Ibn al-Mubarak said, “I sit with the companions and the successors. I look into their books and what they left behind. What would I do with you? You backbite people.”
Source: Siyar A’lām al-Nubalā’ 8/398
عن شَقِيقٌ الْبَلْخِيّ قِيلَ لِابْنِ الْمُبَارَكِ رحمه الله إِذَا أَنْتَ صَلَّيْتَ لِمَ لَا تَجْلِسُ مَعَنَا قَالَ أَجْلِسُ مَعَ الصَّحَابَةِ وَالتَّابِعِينَ أَنْظُرُ فِي كُتُبِهِمْ وَآثَارِهِمْ فَمَا أَصْنَعُ مَعَكُمْ أَنْتُمْ تَغْتَابُونَ النَّاسَ
8/398 سير أعلام النبلاء الطبقة السابعة عبد الله بن المبارك