We Read in Riyadh An-Nadhirah, Imam Sayid Muhibbudin Tabari, page 96,Hadith #1275:
1275 - And from him, it was said that he used to say: "I am the servant of Allah and the brother of the Messenger of Allah ﷺ, and I am the greatest truthful one (Al-Siddiq al-Akbar). Indeed, I prayed before the people by seven years.
Alkarbala