وَقَالَ مُسْلِمٌ: وَسَمِعْتُ أَبَا غَسَّانَ مُحَمَّدَ بْنَ عَمْرٍو الرَّازِيَّ، قَالَ: سَأَلْتُ جَرِيرَ بْنَ عَبْدِ الْحَمِيدِ، فَقُلْتُ: الْحَارِثُ بْنُ حَصِيرَةَ لَقِيتَهُ؟ قَالَ: نَعَمْ، شَيْخٌ طَوِيلُ السُّكُوتِ، يُصِرُّ عَلَى أَمْرٍ عَظِيمٍ.
Translation: Muslim said: I heard Abū Ghassān Muḥammad b. ʿAmr al-Rāzī say that he asked Jarīr b. ʿAbd al-Ḥamīd whether he had met al-Ḥārith b. Ḥaṣīrah. Jarīr replied that he had: the man was notably silent yet persisted in a grave matter.
«وَقَالَ مُسْلِمٌ» introduces the compiler’s own transmission, while the description is Jarīr’s reported wording. The precise identity of the “grave matter” is not stated in this passage; assigning a particular allegation to it would go beyond the evidence.