Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Prophet Muhammad (peace and blessings be upon him) said: "Among my Ummah, the most merciful towards my Ummah is Abu Bakr. The strictest regarding the matters of Allah is Umar. The most truthful in modesty is Uthman. The greatest scholar of Allah’s Book is Ubayy bin Ka’b. The greatest scholar of inheritance is Zayd bin Thabit. The greatest scholar of what is lawful and unlawful is Mu’adh bin Jabal. Every Ummah has a trustworthy one, and the trustworthy one of this Ummah is Abu Ubaidah bin Jarrah."