Sahih Bukhari Volume 5, Book 58, Hadith Number 264.

Narated By ‘Ubaidullah bin Ad bin Khiyair : I went to Uthman. After reciting Tashah-hud, he said,. “Then after no doubt, Allah sent Muhammad with the Truth, and I was amongst those who responded to the Call of Allah and His Prophet and believed in the message of Muhammad. Then took part in the two migrations. I became the son-in-law of Allah’s Apostle and gave the pledge of allegiance to him By Allah, I never disobeyed him, nor did I deceive him till Allah took him unto Him.”