Abu Saeed Khudri reported,

I was sitting in Madinah in a gathering of the Ansar when Abu Musa came to us alarmed, or frightened.We asked, "What is the matter with you?"He said, "Umar sent for me to come to him, so I went to his door and greeted him three times. He did not answer me, so I went back. Then he said, 'What kept you from coming to us?'I said, 'I did come to you. I greeted you at your door three times and they did not answer me, so I went back. The Messenger of Allah ﷺ said, "If one of you asks permission three times and is not given permission, let him go back."'Umar said, 'Bring me proof of that, or I will make you suffer for it.'"Ubayy bin Kaab said, "No one will go with him but the youngest of the people."Abu Saeed said, "I said, 'I am the youngest of the people.'"Ubayy said, "Then go with him."Ibn Abu Umar added in his version, Abu Saeed said, "So I got up with him, went to Umar, and testified."

Muslim 5627

Sahih

حدثنا قتيبة بن سعيد وابن أبي عمر قالا حدثنا سفيان عن يزيد بن خصيفة بهذا الإسناد وزاد ابن أبي عمر في حديثه قال أبو سعيد فقمت معه فذهبت إلى عمر فشهدت

مسلم 5627صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Etiquette
Chapter
Permission to enter
Numbering
Darussalam 5627
Muslim 5627