His knowledge of Hadith
Do you know Imām Shuʿbah was an expert in Hadith narration too?
It is narrated that Sufyān ibn ʿUyaynah was once in a gathering with Imām Shuʿbah when he was enquired about a hadith matter, to which he responded “You cannot ask me about Ḥadith as long as this sheikh (Shuʿbah) is amongst us.”
This undoubtedly indicates that he was not only an expert in Qurʾān, but an expert in Ḥadith as well.