Sahih Bukhari Volume 005, Book 057, Hadith Number 045.
Narated By 'Ubaid-ullah bin 'Adi bin Al-Khiyar : Al-Miswar bin Makhrama and 'Abdur-Rahman bin Al-Aswad bin 'Abu Yaghuth said (to me), "What forbids you to talk to 'Uthman about his brother Al-Walid because people have talked much about him?" So I went to 'Uthman and when he went out for prayer I said (to him), "I have something to say to you and it is a piece of advice for you " 'Uthman said, "O man, from you." (Umar said: I see that he said, "I seek Refuge with Allah from you.") So I left him and went to them. Then the messenger of Uthman came and I went to him (i.e. 'Uthman), 'Uthman asked, "What is your advice?" I replied, "Allah sent Muhammad with the Truth, and revealed the Divine Book (i.e. Quran) to him; and you were amongst those who followed Allah and His Apostle, and you participated in the two migrations (to Ethiopia and to Medina) and enjoyed the company of Allah's Apostle and saw his way. No doubt, the people are talking much about Al-Walid." 'Uthman said, "Did you receive your knowledge directly from Allah's Apostle ?" I said, "No, but his knowledge did reach me and it reached (even) to a virgin in her seclusion." 'Uthman said, "And then Allah sent Muhammad with the Truth and I was amongst those who followed Allah and His Apostle and I believed in what ever he (i.e. the Prophet) was sent with, and participated in two migrations, as you have said, and I enjoyed the company of Allah's Apostle and gave the pledge of allegiance him. By Allah! I never disobeyed him, nor did I cheat him till Allah took him unto Him. Then I treated Abu Bakr and then 'Umar similarly and then I was made Caliph. So, don't I have rights similar to theirs?" I said, "Yes." He said, "Then what are these talks reaching me from you people? Now, concerning what you mentioned about the question of Al-Walid, Allah willing, I shall deal with him according to what is right." Then he called 'Ali and ordered him to flog him, and 'Ali flogged him (i.e. Al-Walid) eighty lashes.