Abu Musa asked permission to come in to 'Umar three times, but he did not give him permission. So he went back. Then 'Umar met him and said: Why did you go back? Abu Musa said: I heard the Messenger of Allah (PBUH) saying: Whoever asks permission three times and is not given permission, he should go back. 'Umar said: Prove it or I will do this and that. So he went to a gathering of his people and implored them by Allah Almighty [to testify]. So I said: I am with you. So they testified to that, and 'Umar released him.