I heard ‘Uthman (رضي الله عنه) delivering a khutbah from the minbar. He said: I used to buy dates from one of the Jewish clans who were called Banu Qainuqa`, and sell them at a profit. News of that reached the Messenger of Allah (ﷺ) who said: `O `Uthman, when you buy, take your dues with nothing extra, and when you sell, give (the other party`s) dues with nothing less.`
`Ubaidullah bin `Adiyy bin al-Khiyar narrated that `Uthman (رضي الله عنه) said to him:
Verily Allah, may He be glorified and exalted, sent Muhammad (ﷺ) with the truth and I was one of those who responded to (the call of) Allah and His Messenger, and I believed in that with which Muhammad (ﷺ) was sent. Then I migrated twice, and I also attained the honour of becoming the son-in-law of the Messenger of Allah (ﷺ); I swore allegiance to the Messenger of Allah (ﷺ), and by Allah, I never disobeyed him or betrayed him until Allah, may He be glorified and exalted, took his soul in death.