Musannaf Ibn Abi Shaybah

Hazrat Saleem bin Hanzalah narrates that we went to Hazrat Ubayy bin Ka'b so that we could converse with him. When he stood up, we also stood up and began to walk with him. Then Hazrat Umar met him and raised a whip over him. He (Ubayy) said: O Commander of the Faithful! Be aware of what you are doing! He (Umar) said: Indeed, what you see here is a trial for the one who is followed and a humiliation for the follower.