Abu Saeed Khudri reported,

Abu Musa sought permission to enter upon Umar three times, but Umar did not grant him permission, so he went away. Umar later met him and asked, "What is the matter with you, that you turned back?"Abu Musa replied, "I heard the Messenger of Allah ﷺ say, 'Whoever seeks permission three times and is not granted it should turn back.'"Umar said, "You must bring proof for this, or I will surely do such and such to you."So he went to the gathering of his people and implored them by Allah to bear witness for him. I said, "I am with you," and they testified to that for him, so Umar let them go on their way.

حدثنا يزيد أنبأنا داود عن أبي نضرة

عن أبي سعيد الخدري قال

استأذن أبو موسى على عمر ثلاثا فلم يأذن له عمر فرجع فلقيه عمر فقال ما شأنك رجعت قال سمعت رسول الله ﷺ يقول من استأذن ثلاثا فلم يؤذن له فليرجع قال لتأتين على هذا ببينة أو لأفعلن ولأفعلن فأتى مجلس قومه فناشدهم الله عز وجل فقلت أنا معك فشهدوا له بذلك فخلا سبيلهم