وَحَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ الْحَنْظَلِيُّ، قَالَ: سَمِعْتُ بَعْضَ أَصْحَابِ عَبْدِ اللَّهِ، قَالَ: قَالَ ابْنُ الْمُبَارَكِ: نِعْمَ الرَّجُلُ بَقِيَّةُ، لَوْلَا أَنَّهُ كَانَ يَكْنِي الْأَسَامِيَ وَيُسَمِّي الْكُنَى؛ كَانَ دَهْرًا يُحَدِّثُنَا عَنْ أَبِي سَعِيدٍ الْوُحَاظِيِّ، فَنَظَرْنَا فَإِذَا هُوَ عَبْدُ الْقُدُّوسِ.
Translation: Isḥāq al-Ḥanẓalī transmits through an unnamed companion of Ibn al-Mubārak: Baqiyyah would have been an excellent man except that he disguised names as kunyahs and kunyahs as names. He had long transmitted from “Abū Saʿīd al-Wuḥāẓī,” who on investigation proved to be ʿAbd al-Quddūs.
“He used kunyahs for names and names for kunyahs” means that source identification became obscure. Once “Abū Saʿīd” was identified as ʿAbd al-Quddūs, the existing evidence about that particular transmitter became relevant to the chain.
The upper isnād separately contains «سَمِعْتُ بَعْضَ أَصْحَابِ عَبْدِ اللَّهِ» (“I heard one of ʿAbd Allāh’s companions”). That intermediary remains unnamed. Al-Nawawī calls him «مَجْهُولٌ» and states: «وَلَا يَصِحُّ الِاحْتِجَاجُ بِهِ، وَلَكِنْ ذَكَرَهُ مُسْلِمٌ مُتَابَعَةً لَا أَصْلًا»: this route is not independent proof; Muslim includes it as a supporting *mutābaʿah*, not as an *aṣl* on which to rely by itself. Do not confuse the still-unknown intermediary with “Abū Saʿīd al-Wuḥāẓī,” whose identity is revealed as ʿAbd al-Quddūs.