Abbad bin Zahir reported,
I heard Uthman 
delivering a sermon, in which he said, "By Allah, we accompanied the Messenger of Allah ﷺ on journeys and at home. He used to visit our sick, follow our funeral processions, fight alongside us in battle, and share with us whatever he had, whether little or much. Yet there are people now trying to instruct me about him, when it may well be that not one of them ever laid eyes on him."
Ahmad 504
Hasanحدثنا محمد بن جعفر حدثنا شعبة عن سماك بن حرب قال سمعت
عباد بن زاهر أبا رواع قال
سمعت عثمان رضي الله عنه يخطب فقال إنا والله قد صحبنا رسول الله ﷺ في السفر والحضر وكان يعود مرضانا ويتبع جنائزنا ويغزو معنا ويواسينا بالقليل والكثير وإن ناسا يعلموني به عسى أن لا يكون أحدهم رآه قط
Its chain of transmission is hasan. Abbad bin Zahir, Abu Hatim said, "An acceptable narrator." Dulabi said in Kuna 1:172, "He heard from Uthman bin Affan." I did not find anyone who mentioned any criticism of him, so his standing leans toward being considered reliable, Allah willing, especially since he is among the early Tabiin.His kunya is Abu Ruwa. Al-Hafiz said in Tajil, "Mizzi vocalized it in his own handwriting with a damma on the ra and without doubling the waw, and it is likewise found in a reliable manuscript of Ibn Abu Hatim's book, and in Ibn Kathir's own handwriting, 'This is how our teacher vocalized it.'"Ibn Kathir said, "What I recall is with a fatha on the ra and a doubled waw."We give preference to what is established through the precise vocalization found in the handwriting of the leading scholars.