What must be preserved when reading «qāla Abū Isḥāq ... wa-ḥaddathanā»?

Reports of ʿAmr ibn ʿUbayd: Attribution, Conflicting Accounts and Evidence of Criticism

• Treat Abū Isḥāq’s statement as a separate critical matn
• Place Muḥammad b. Yaḥyā’s upper route below Nuʿaym
• Keep the added upper chain and its speaker distinct
• Classify the shared route below Nuʿaym as a second independent chain