One day Allah's Messenger (ﷺ) came out (before the people) and `Abdullah bin Hudhafa stood up and asked (him) "Who is my father?" The Prophet (ﷺ) replied, "Your father is Hudhafa." The Prophet (ﷺ) told them repeatedly (in anger) to ask him anything they liked. `Umar knelt down before the Prophet (ﷺ) and said thrice, "We accept Allah as (our) Lord and Islam as (our) religion and Muhammad as (our) Prophet." After that the Prophet (ﷺ) became silent.
Sahih al-Bukhari Book 3, Hadith 35
← Previous Hadith The Prophet (ﷺ) was asked about things which he did not like, but when the questioners insisted, the Prophet got angry. He then said to the people, "Ask me anything you like." A man asked, "Who is my father?" The Prophet (ﷺ) replied, "Your father is Hudhafa." Then another man got up and said, "Who is my father, O Allah's Messenger (ﷺ) ?" He replied, "Your father is Salim, Maula (the freed slave) of Shaiba." So when `Umar saw that (the anger) on the face of the Prophet (ﷺ) he said, "O Allah's Messenger (ﷺ)! We repent to Allah (Our offending you).

Sahih al-Bukhari Book 3, Hadith 34 Next Hadith → Whenever the Prophet (ﷺ) asked permission to enter, he knocked the door thrice with greeting and whenever he spoke a sentence (said a thing) he used to repeat it thrice. (See Hadith No. 261, Vol. 8).

Sahih al-Bukhari Book 3, Hadith 36