“Shams al-Din al-Dhahabi”, one of Sunni scholars says about Imam “Baqir” [AS]:
ابوجعفر الباقر ،سیّد امام فقیه،یصلح للخلافة؛
“Abu-Ja’far Baqir” was sayyid and faqih and the one who was qualified for caliphate.
Siyar al-A’lam al-Nubala – al-Dhahabi – vol. 13, p 120