حَدَّثَنِي الْفَضْلُ بْنُ سَهْلٍ، قَالَ: حَدَّثَنَا يَزِيدُ بْنُ هَارُونَ، قَالَ: أَخْبَرَنِي الْخَلِيفَةُ بْنُ مُوسَى، قَالَ: دَخَلْتُ عَلَى غَالِبِ بْنِ عُبَيْدِ اللَّهِ فَجَعَلَ يُمْلِي عَلَيَّ: حَدَّثَنِي مَكْحُولٌ، حَدَّثَنِي مَكْحُولٌ. فَأَخَذَهُ الْبَوْلُ فَقَامَ، فَنَظَرْتُ فِي الْكُرَّاسَةِ فَإِذَا فِيهَا: حَدَّثَنِي أَبَانٌ عَنْ أَنَسٍ، وَأَبَانٌ عَنْ فُلَانٍ. فَتَرَكْتُهُ وَقُمْتُ.
Translation: Al-Faḍl ibn Sahl narrated to me: “Yazīd ibn Hārūn narrated to us; he said: Khalīfah ibn Mūsā informed me: ‘I entered upon Ghālib ibn ʿUbayd Allāh, and he began dictating to me, “Makḥūl narrated to me; Makḥūl narrated to me.” Then he was overcome by the need to urinate and got up. I looked into his notebook and found written there, “Abān narrated to me from Anas,” and “Abān from so-and-so.” So I left him and stood up to depart.’”
The oral source differed from the written notes. Comparing notebooks, documented hearings and parallel routes can expose an attribution problem; in this account the observed inconsistency undermined confidence in the narrator.