Narrated Anas:
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).
| Reference | : Sahih al-Bukhari 94 |
| In-book reference | : Book 3, Hadith 36 |
| USC-MSA web (English) reference | : Vol. 1, Book 3, Hadith 94 |
| (deprecated numbering scheme) |