The Messenger of Allah ﷺ said, "The most merciful of my ummah toward my ummah is Abu Bakr. The strictest of them in the matter of Allah is Umar. The most truthful of them in modesty is Uthman. The best reciter of the Book of Allah among them is Ubayy bin Kaab. The most knowledgeable of them in inheritance laws is Zayd bin Thabit. The most learned of them concerning the lawful and the unlawful is Muaz bin Jabal. Indeed, every nation has a trustee, and the trustee of this ummah is Abu Ubayda bin Jarra."This is a hasan sahih hadith.
حدثنا محمد بن بشار حدثنا عبد الوهاب بن عبد المجيد الثقفي حدثنا خالد الحذاء عن أبي قلابة
قال رسول الله ﷺ أرحم أمتي بأمتي أبو بكر وأشدهم في أمر الله عمر وأصدقهم حياء عثمان وأقرؤهم لكتاب الله أبي بن كعب وأفرضهم زيد بن ثابت وأعلمهم بالحلال والحرام معاذ بن جبل ألا وإن لكل أمة أمينا وإن أمين هذه الأمة أبو عبيدة بن الجراح هذا حديث حسن صحيح
[Its chain of transmission is sahih]. Ibn Majah also narrated it in the Introduction, the merits of Khabab, h: 154, from the hadith of Abdul-Wahhab, and Bukhari, h: 4382, from the hadith of Khalid Haddan, both from him, and Ibn Hibban graded it sahih, h: 2218, as did Hakim, 3/422, according to the criterion of the two Shaykhs, and Dhahabi agreed with him.