Ubayd ibn Hunayn related to him that Abu Musa said, "I asked permission three times to come in to 'Umar, but he did not give me permission and so I went away. He said, ''Abdullah, is it hard on you to be kept waiting at your door.' I said, 'I asked permission from you three times and you did not give me permission, so I went away (and we were commanded to do that).' 'Umar said, 'From whom did you hear this?' I replied, 'I heard it from the Prophet, may Allah bless him and grant him peace.' 'Umar said, 'Did you hear something from the Prophet (ﷺ) which I did not hear? If you do not bring me a clear proof, I will make an example of you!' Therefore I went to a group of Ansar who were sitting in the mosque. I asked them and they said, 'Does anyone doubt this?' I told them what 'Umar had said. They said, 'Only the youngest of us will go with you.' So Abu Sa'id al-Khudri - or Abu Mas'ud - went with me to 'Umar. He said, 'We went out with the Prophet (ﷺ) when he was going to Sa'd ibn 'Ubada. He gave the greeting, but Sa'd did not give permission. Then he greeted him a second time and then a third time, but Sa'd did not give him permission. So the Prophet said, 'We have done what we must.' Then he went back and Sa'd caught up to him and said, 'Messenger of Allah! By the One who sent you with the Truth, every time you greeted me, I heard and answered you, but I wanted to have a lot of greeting (peace) from you for me and the people of my house.'" Abu Musa said, "By Allah, I am a guardian of the hadith of the Messenger of Allah (ﷺ)." 'Umar said, "Yes, but I wanted to make sure."